Brando
2:43AM yes I do the same. Enable your Realtek or whatever in Windows as your default device. In Sonar, exclude it and only select the sound card and drivers you want SONAR to use. Works well. I keep a small set of PC speakers tied to my built in card just for windows sounds and for media player etc.

 
Same here using the built in Realtek sound as mydefault device for windows, etc.  When running Sonar, I swithch to my VS 100 and it works all the time.

I haven't had any crashes, dropouts, etc.  But, I mostly only do audio tracks. On occasion I will also have one or two MIDI tracks. 
 
My PC is a recent build and is very stable on both Windows 7 64 bit and Windows 8 64 bit. 

2:43AM
Overall, things are getting better for me. I think that by completely axing all the 32-bit, crappy plugins from my arsenal and slightly increasing my buffer size did the trick. Of all the 32-bit plugins that I still do use, they come from reputable companies and seems to be coded well. Hence, I try to stay away from any SynthEdit or Synthmaker plugins unless they're from Variety of Sound, for example; they seem OK. Also, most everyone's sigs omit their motherboards, and in my opinion, this is one of the most critical components in one's system, more so than listing several HDD/SSD's and/or their collection of dot-matrix printers. Not all motherboards are created equal. For example, I had to part ways with my beloved Gigabyte mobo (GA-EP45-UD3P) simply because it had inherent latency issues and was no-way compatible with anything related to music production. And since I run a slightly older system, Intel Core2Duo Quad Q9550 and had no intention to upgrade all components to an i7, I bought a new-old stock P5Q mobo and it made a world of difference. So in my opinion, someone that reports a great system based on their signature that doesn't list the mobo may only paint half the picture. 

jb101
Like John, I use internal sound card for windows, etc.

Jb101, what does this mean exactly?  Do you somehow only run Sonar on your interface while Windows defaults to the internal? Maybe I should try this as some Windows apps force my interface from 48kHz to 44.1kHz, which results in silence and annoyance. This occurs despite the Windows default set at 48kHz, 24-bit.

Yes, I only run Sonar and a couple of other programs through my interface, and and leave my internal card as default for windows sounds, etc. I have quite a nice computer set of speaker set up to the internal card, and it's handy to be cake to watch tutorial videos, youtube etc. whilst running Sonar. I can always change it if , for example, I want to listen to media player through my main monitors or my nearfields.

Please excuse any typos, struggling with my smart phone today.

I had a crash...maybe 2 months ago. It was the only one that I can remember having with X2a. The funny thing was the only thing I did was open a rescent project, then realized that it was the wrong one, so I went to close it and then came the crash. I suspect that the project was not fully done opening up when I tried to close it, even though it appeared to be.

I do mostly audio, with midi drums and an occasional midi piano.; 20-24 tracks, lots of plugs. Other than this one crash, rock solid.

I am running an AMD Quadcore Phenom, Vista 64, 6GB ram, off the shelf HP.

The only consistent, albeit rare, Sonar crash for me is to set up a loop and give editing a major workout while looping. More repeats increases the odds of a freeze, so if I remember to hit stop occasionally and re-start the loop, it avoids the problem.
 
Very rarely I'll have freezes when dragging audio from my external samples drive into track view when using the browser. I think it may relate to when the hard drive has turned itself off from not being used, then has to spin up but I haven't verified that. As Herman Cain would say, "I don't have the facts to back me up" but maybe Sonar goes out to look for something and when it can't find it, it gets upset.
 
Overall, though, Sonar just says "yessir" and does what I want it to do...that's why I use it.

Running fine here. I use only 64 bit plugs. One project is rock/metal, so mostly audio tracks, drums are midi. The other project I'm a part of is EDM and is all midi, vst, with automation and effects galore. I have tried to reproduce some of the bugs that people have posted on the forum but so far can't repeat the results and overall can't seem to get X2 to stumble. I don't use dual monitors or touch screen though, so I can't speak for those glitches. It appears a lot of people seem to have relatively smooth setups but dual monitor and touch, introduces some weirdness...

X2a for the most part has been stable for me recently as I've switched up my typical project from Session Drummer 3, Dimension Pros and Raptures, to Kontakt, Trilogy, and (sometimes) BFD. Actually, this particular project I'm working on with the latter arrangement of synths has been stable for hours and hours but just now as I was editing an envelope on perhaps quite literally the last edit before rendering to a WAV file SONAR crashed with an unhandled exception error.
 
SP
 
EDIT: I should also mention that I don't have dropout issues at all. I run SONAR on Win 8 x64 on an older i7 965 with 16gigs of RAM. Audio interface is a Roland Octa-Capture, using ASIO drivers of course at 128 sample buffer at 24/48.

Sonar X2a has been very stable for me. No dropouts. Crashes have only been related to specific plugins, not the actual software. What's my system? I have a Mac running Boot Camp. Maybe that has something to do with it -- you know, that Mac vibe. :)

I have not upgraded yet.  I'm waiting for the $1.99 special.  X1 was the program that made recording effortless.  It was so bad, that it was no longer worth the effort.
 
 
 

After many hours of use I must say I've not had a crash or a dropout. Running as many as 60 tracks , the largest number, most VST inserts. X2-A has been rock solid for me from the beginning. Running a PreSonus interface/ASIO along with a MCU-Pro.
 
Pro who ? :)
 
Best Regards,
 
Bill -
CHO