This is simply what happens when there are just assumptions, wrong conclusions and no facts to point to.
"I don't trust it" or "it works in the previous Sonar version" or "It can't be Sonar" does not diagnose the problem.
There is definitely however a major big clue in the very first post where the OP writes:
 
Always loses my audio driver.
 
That is definitely without a doubt pointing to firmware or drivers issue...

The OP however concludes several times by saying that Platinum should behave like X3, therefore it's a Platinum issue. It may seem like an obvious conclusion, but that is a completely wrong assumption. 

Bob had the right idea here which must have taken him a bit of time to type out and looks extremely helpful to me:
http://forum.cakewalk.com/FindPost/3202104
 
The OP could post some answers to Bob's questions which will probably help resolve his issue, or maybe he will just disappear into thin air because it seems he clearly thinks it is Sonar (so that's that - we can all go home).

The facts are though that those diagnosing the issue right now (including the OP) have absolutely nothing to go on right now other than "Always loses my audio driver.". 
 
From the sound of it the OP just hasn't had much experience in diagnosing PC issues, however if he needs a hand he could do no better than here should he so wish to engage with those who want to help him resolve his issue.

I stand ready to assist, if detail can be provided by the OP - all I can offer is my best efforts to help, but maybe between us we can get some things resolved.
 
Bob Bone
 

jamesyoyo
3 kontakt 5 64-bit
2 Philharmonik 32-bit

I have not gotten through this whole thread and realized I was getting diverted by reading it so went back to the OP.
 
Due to issues I have read with 32-bit plugs in 64-bit SONAR, I have avoided these like the plague since X1/X2. I have played with some and they seemed to work fine, but not done a project with any. I have seen "Philharmonik" in a few issue threads, but do not have it, so can offer nothing other than to see if disabling that helps.
 
As far as the OP, I am 100% in agreement with the initial reaction of "works in X3, doesn't work in Platinum is an issue." Who would not come to that same conclusion (especially on the same machine)?
 
I find the current mindset more than a bit disconcerting.

Doc:
 
I have been using Sonar a looooong time.
I have produced hundreds of songs on Sonar, in just about every conceivable genre.
I have upgraded every opportunity, such is my appreciation of the product.
I used to run my own computer company.
I keep my firmware and drivers on all my audio devices up to date.
My display drivers are up to date.
If I was experiencing issues with a project that was imported from anything other than the previous version of Sonar, I would say that my complaints were frivolous at best.
But the spring-to-Sonar's-defense reflex that many show around here to me speaks more of some post-purchase confirmation bias than anything else. I admit I have done it in the past.
The few folks who do know me around these forums can tell you that I have had major issues with complex projects in every new release. I am not here to ****.

With respect none of those directly answer Bob's questions, with further respect it appears you have already diagnosed the issue yourself (how?), and from what you write it appears you don't want anybodies help as you have already jumped to conclusions. Fair enough but...

You should get over the idea about whether or not is Sonars fault. Right now you have supplied no real evidence to jump to any conclusion and yet you have done that. It may work in earlier versions but this is a conplete red herring if you know anything about software configuration. Sorry but this is a fact.

Either give people a chance to help you or stop pointing to an issue that you have no idea of the cause. Their intentions are not to be fanboys but to help you. It looks like (for instance) Bob has had a lot more experience of tackling these sorts of issues than you have, you can talk about your crentials till the cows come home it's how his writing that shows more technical expertise.

Doktor Avalanche
With respect none of those directly answer Bob's questions, with further respect it appears you have already diagnosed the issue yourself (how?), and from what you write it appears you don't want anybodies help as you have already jumped to conclusions. Fair enough but...

You should get over the idea about whether or not is Sonars fault. Right now you have supplied no real evidence to jump to any conclusion and yet you have done that. It may work in earlier versions but this is a conplete red herring if you know anything about software configuration. Sorry but this is a fact.

Either give people a chance to help you or stop pointing to an issue that you have no idea of the cause. Their intentions are not to be fanboys but to help you.

Doc:
 
If you read my posts, in no way did I ever ask anyone for help on resolving the issues; the nice people who responded lept to that conclusion. I simply stated my disappointment and disbelief at the situation and wondered if anyone else felt the same way.

jamesyoyo
I simply stated my disappointment and disbelief at the situation and wondered if anyone else felt the same way.

Well you said

jamesyoyo
"This piece of crap version"

jamesyoyo
"Anyone else looking to get their money back?"

You say you are technical and yet everything below you write is completely wrong if you've had some experience in diagnosing PC issues... I'm sorry I wish I could be more polite about this... and I would go into more detail but I think you would immediately dismiss it (others have anyway).

jamesyoyo
" If a project works well in the old version and not the new, then the de facto reaction is the new version of the SAME EXACT PRODUCT has issues. "

jamesyoyo
"So I try to open it in X3....no problem! Ergo onw must conclude that there is something inherently buggy with the Platinum version of the software."
..."the empirical evidence speaks for itself."

jamesyoyo
"But again: is it unreasonable to expect a project to work in Platinum that is working perfectly fine in X3?"

Just to requote:
 

jamesyoyo
I simply stated my disappointment and disbelief at the situation and wondered if anyone else felt the same way.

Are you assuming that everybody has exactly the same situation as you? Because if that is the case... from somebody who used to have their own computer company that's a bit of a weird thing to do. People using software can have any number of issues, especially when using DAW software. Or is this just a general - Sonar is rubbish post... Otherwise I can't understand the motivation.
 
FWIW - I don't experience your issues - go figure...

Anyway good luck with tech support.... Keep us informed.
 

I forgot to say btw I too had a lot of issues upgrading from X3 to Platinum. They were either plugin, project or driver specific. It was very fraustrating. I regard myself as an advanced user and yet this was hard to diagnose. I am not looking for a refund because so far I've managed to find solutions that do not point to Platinum itself. It took a long time to find answers, it was frustrating but I did find them. I have only one mystery left.

Hey Jamesyoyo, I am right there with you when it comes to agreeing on Platnum handles my X3e material with more crashing.
  I built a 2nd PC AMD 8-core to try to move on. But I still like the Platinum version, I`ll work it out as long as I have the time to, but I already know the quirks well enough in X3e.
 I won`t forget what I went thru to get where I did. I`m not moving projects into Platinum unless I have re-intregration time to work out those quirks again. At the moment Platinum crashes/hangs more than X3e. This is on 2 different PCs, 1 is Intel and the other is AMD.
 Every update to me, forces me to have to work at newer workarounds. I have slowly been moving my top 5 projects in to Platinum, but that is extra "verification" time, I confess spending to much time on "techie" work. I wished upgrades went smoother, but every upgrade has been worth the struggle. Sonar is very cool, Platinum is making things even better, so we evolve as they evolve.
After all, it`s all about the music. No show stoppers here, I`m having lots of fun. I barely have anytime to post here. The guys here on the forum are fun to read on a daily basis. They save me so much debug time. Everyday, there is something here well worth reading.
 
So yeah, I think things are slightly different in Platinum too.
 
 
 
 

This is starting to remind me of the Steam forums.