This is probably more of a Windows issue than a SONAR issue, but it's driving me batty.  And it only happens in SONAR, though that could be just a coincidence because I use SONAR more than any other piece of software.
 
The issue is, every few days something happens to SONAR where it stays on top of all other windows.  So for example, if I need to check my email, I have to minimize SONAR in order to see Outlook.  Clicking on the taskbar doesn't help-- all other windows stay behind SONAR.  If I need to open a clip in Sound Forge I have to minimize SONAR in order to see it.  Even alt-tab doesn't help.
 
Doesn't sound like a big deal, but...  how am I suppose to play poker while I work if my poker tables don't pop up when it's my turn to act??!!
 
I'm running SONAR non-maximized (stretched across two monitors) in Windows Vista 64.  Any ideas?  A complete restart fixes the problem but that's obviously a pain.  Restarting just SONAR does not fix the problem.
 
Thanks!

I've had the same problem since upgrading to 8 but it doesn't happen everytime. I just minimize SONAR and then click on other things and then it's fine the next time I restart SONAR. It's just at initial startup it does something funky with the video drivers. I have no fix. I'm just lending support in that you're not alone.

This just started happening with me this week.
 
I've never had it happen before.
 
v8.5

M

Does alt or Windows button plus tab key work?

Thanks for the replies.
 
I am on Windows 7 Pro x64 with a DAW and SONAR install I have been running for about a year. As the original posters pointed out it doesn't happen all the time, but when it does the other windows simply will not stack on top of SONAR. I have to minimize SONAR to see the other windows. This includes both free standing apps such a MS Paint (when I am grabbing a screen shot) as well as dialog boxes that open within SONAR (Cakewalk Plug In Manager) but end up displayed underneath. 
 
Clicking on the icons in the taskbar does not help... I can see the window pop open but then it disappears underneath.
 
If I close SONAR and relaunch it then it is usually OK again. I just did a bunch of updates to Native Instruments, Studio One 2, and some third party effects, but otherwise I can't figure out what might have changed.
 
I did notice that a function I thought I turned off seems to have come back to life: If I drag a app window up near the top of my display screen it auto snaps it to maximized. I can't remember how/where I turned that off before.
 
I'll try the suggestions made by Geoff the next time it happens.