I have a midi piano part that is not tight-it seems "off" in certain sections like it's lagging behind or ahead-jumping.  It's auto corrected by 100% so it's not that.  I've use both a Kurzweil MicroPiano and Cakewalk's TruePiano.  When I render the Kurzweil midi part into audio it stills is off but also I'm getting cracks & pops in the audio.  When I tried it with TruePiano the midi part was "off" but also cracked & popped during midi playback.  Now this was all happening in X3.  When I put the project in Platinum there wasn't any problem.  So what is off in X3.  I use both versions.  Thanks

With out your system specs I can only guess. 
Is your PC optimized for audio? are you using on board audio or an interface.

Just out of curiosity, if you have Platinum, why are you still using X3?

1st question: I have a full blown DAW Windows 8-Fireface 400 by RME
 
2nd question:  I'm using X3 on older projects that I initially did in X3.  Some of the fx that I used in X3 aren't recognized by Platinum and I'm too lazy to re-do everything when what I have is OK.  All my new projects I use Platinum

What effects are recognized by X3 that aren't recognized by Platinum?

Cakewalk FxReverb, FXChorus.  I use these extensively but when I open a project in Platinum that I started in X3 I get a dialog box: The following plug-ins referred to in this project could not be found.  Platinum evidently discontinued these plug ins which I happened to like and used a lot.  I know there are other plug ins that will accomplish the same thing in Platinum, but I'm just used to these.

If they still exist on your system, you should be able to include the path in your VST scan and get them into Platinum.
 
Are these the cakewalk DX effects?  If so, I do have them in Platinum.  If not, I don't know which ones they are because I don't have them in either Platinum or X3.
 
Also, what driver mode are using with your interface and what are you system specs (e.g. cpu, memory, etc.)?

Yes it seems odd you would need to use X3, I have both as well but I've not opened x3 in over a year. If you install sonar versions in order of oldest to newest, all the VST's and Plug ins will load into the latest version,, all of them.   I install bare bones of 8.5 just to get the few things discontinued later on. 
I think you just need to mess about in Splats plug in manager and get those X3 plugs in the scan path. But far as I know all Sonar versions used the same folders. 
 

Thanks to all.  Yes, these are DX effects. When I'm in Platinum and go to Plug In Manager, I just see Sonitus Direct X plug ins and not any of the Cakewalk Direct X Audio Effects that are listed in X3  If they are still in my system some how, I'm not too sure how to find them.  What is Splats plug in manager?  If anyone can give me a step by step way of finding these I'd appreciate it.

Tropical Cowboy
 What is Splats plug in manager?  If anyone can give me a step by step way of finding these I'd appreciate it.

It's where you organize your plug ins