As per title - 
 
I have clients waiting, and this immense f**kup can not be tolerated much longer. X1 does not have this problem.
I have an i7/2.93 GHz (not too shabby), 16GB RAM, 4 WD Caviar Black 7200 with separated audio, program and samples etc.
 
Could someone point me in the right direction regarding this "HUDnowtime"-message that pops up from time to time after crash, and what to do to fix it?

Please elaborate on the plugins this particular project uses.
 
Also, load up the project in Safe Mode in Sonar, and do not load any plugins.  Now see if this continues to occur.
 
In addition, you can try to load up the project as normally done in Sonar and hit the letter 'E' on your computer keyboard.  This will toggle off/on the bypassing of all effects.
 
With either of the above two things to try, if the project plays fine with no effects, then one or more of them may be failing, and you would need to go through determining which ones are causing these issues.
 
The most likely place I could point you to is to look for any 32-bit plugins present in a 64-bit install of a Sonar project.  Sometimes these do not play nicely together.
 
Bob Bone
 

I've got the same problem.  It's been happening ever since I removed an m-audio keystation 88es from my workstation earlier today.
 
Sonar X2 Producer crashes (gives a "not responding" msg) in as little as 5 minutes and as long as 20 minutes.  When I pull up the task manager, I see SONAR and HUDNowTimeFB are both not responding.  I don't know what the latter is.  If I kill SONAR and try to restart it, it doesn't fire up.  It requires a reboot before I can get another 5-20 mins.
 
My system specs are not too shabby either.
 
I'll remove my VST plugins and see if that helps.  But again, in my case, the only thing that was different between a stable DAW and the brick I have now is that I uninstalled m-audio keystation 88es.  Strange.

But apparently not any more: http://forum.cakewalk.com/SONAR-X2-crashes-ever-since-I-uninstalled-maudio-keystation-88es-m2955266.aspx#2955291
 

So, if this is resolved, perhaps you could add 'Solved' to the thread subject line?  That would let folks know it all worked out, and they wouldn't review a bunch of posts to find out it had been cleared up.
 
Anyways, hope it is stable now, 
 
Bob Bone