I lost about a half hour's work tonight in Platinum when the program hung while copying and pasting some midi.
 
I had a pretty substantial guitar midi part I had recorded and was altering notes everywhere to create more of a travis pick arrangement with variations. I was simply moving some notes up and down and breaking the bars into measure size chunks. Then I would paste them into another midi track to get the pieces assembled the way I wanted.
 
So basically all I was doing was moving around midi notes and copying a measure at a time to a new track. Nothing intensive, but when I did the absolute last paste and was about to save. Grrrrr ... Platinum stopped responding. I know in the past with X3 if I did have the rare crash and I started up X3, I was offered a temp file to see if there might be a recovery point which usually worked. Platinum offered nothing even though I am sure I have auto saves set every 5 minutes.
 
The only thing weird I noted about working with midi in Platinum is every time I adjusted a note length, the first time I did the adjustment the note would jump back to the original length. When I adjusted it the second time the adjustment took.
 
Don't know if anyone else has had this kind of problem like my crash, but the midi implementation has changed and not for the better as far as I'm concerned.
 

I have had the odd (rare) hang during editing both audio and MIDI in Sonar since I started using it at X1, but nothing that I was ever able to reproduce to submit a problem report. I don't suppose you have Melodyne clips in the project do you? 
 
As for the MIDI notes snapping back when you adjust their length for the first time, I've never seen that. I've been doing a lot of MIDI editing with Platinum and it's honestly been very smooth. Is this something that happens in a fresh project with one MIDI track, or is it just happening in large projects? 

I'm sorry that you lost your work. I'm not sure what caused the crash, but one recommendation I have is to use CTRL+S incessantly. It's become such a habit that I almost do it subconsciously now. I pretty much press it after I've done anything. I close the PRV window - CTRL+S. I add a virtual instrument - CTRL+S. I copy a track - CTRL+S. I record or write any new part - CTRL+S (sometimes twice - haha!). It's such a quick thing to do that it doesn't even interrupt your workflow and can really save you when things like this happen. 

Yes, judicious use of Crtl-S is a necessity in *any* program.  I know it doesn't help you now, but we've all learned the lesson the hard way (me - multiple times.) I've lost 30 minutes of work in excel before, too due to the spinning wheel of frustration (TM).

a forum host should point out that using your email as a username is not the best way to avoid spam

In my problem project I have one instance of SampleTank 3 using a single guitar sound. One midi track I was using for the edits and a single audio track. Using Windows 7 with 16 gig of memory.
 
In terms of the Save command, I usually use it often, but for some reason I was so intent on the editing I was doing that I did not save for quite a while (1/2 hour). I was also counting on the auto save, but after checking I found it was just another preference that did not come over with the upgrade.
 
I have to admit also I've never had any problems before in working with midi in any form of Sonar. I would wonder if anything that has been done for the new painting midi feature has affected the code that supports midi editing.
 
I will be very careful in the future remembering that Platinum is going to need a pretty thorough shake down before it reaches stability.

pwalpwal
a forum host should point out that using your email as a username is not the best way to avoid spam

I was looking for a way to change my user name, but could not find any way to edit it. Can anyone tell me how to change my user name or point me to a faq on this?

you could pm a [cakewalk]er, or maybe a forum host can jump in
 
otherwise, it's dooooooooommmm, all the way;-)

Just had my first crash while changing a setting in AD2. It sent a crash report so hopefully someone will look at the reason.
I have "save" as one of my 9 buttons on the Custom Module and hit it often!
 
Grum.

pwalpwal
a forum host should point out that using your email as a username is not the best way to avoid spam

@Lawrence
Using your email as a username is not the best way to avoid spam.
Contact cakewalk support if you need your username changed, or PM a cakewalk representative. You could also start a new thread in the forum discussion forum to see if this helps.
 
Hosts have no permissions to change your username.