As the other thread pointed out, the only way to roll back is to uninstall/re-install from the discs or download.
I have to be honest though, I'm curious as to the specifics of your issues. I'm curious as to if X2a is indeed less stable for you, or if it is a matter of perception or even coincidence.
We resolved hundreds of bugs with the X2a update (many of them stability related). I personally monitor a lot of the crash reporting that comes in, and the numbers definitely indicate X2a being much more stable the X2. Not to mention a lot of raw functionality fixes went into the update. Rolling back to X2 is guaranteed to be rolling back to a less stable version.
A good place to get started with audio dropouts is with some of the information here:
http://www.cakewalk.com/S...reader.aspx/2007013007 Any version of SONAR can experience dropouts if external factors are getting in the way. Check out the above link if you get a chance to see if it helps. I'm sure the folks here might have a lot of other suggestions as well.
In regards to the GUI going white and freezing, I'd be curious as to what a crash file indicates was the cause. We have an article on our website in regards to how to obtain/create this file if the Fault Reporter in SONAR isn't coming up. If the Fault Reporter is coming up, definitely send the report through. Anyhow, you can find manual instructions for generating the .dmp file here:
http://www.cakewalk.com/S...px/2007013196#MiniDump If you send this file along to Tech Support, they can see if there are any clues to your crash. It could be something internal to SONAR, but it could also be an external factor like a plug-in or device driver. I'd get on the phone with Tech Support if you get the chance to see if they can determine any cause.
It would be a waste to go through the trouble of rolling back to X2 release only to find out it didn't resolve the problem. If you get on the phone with us, best case scenario is that Tech Support is able to help you and you continue on with recording and making music. Worst case scenario is that Tech Support isn't very helpful, but identifies an issue that should be corrected in further updates and escalates it with the goal of making even better future products.
Either way, I would spend a little bit of time investigating.