I just stumbled across this problem as I was cleaning up a snare track. Just going through and dropping the space between the snare hits with a 10dB cut (thinking about audiosnapping an extra midi track for grins) and about a minute into the track, things get sluggish and then next time  - sorry - out of memory! SO, I turn off all the goodies on every track (all 32 of them) save the project. Reboot, fire it all up again using ctrl and the shortcut and...same deal. And of course, anything else I try will not work unless I shut down and restart.
The computer is optimized for the program, clean install X3d with the VS700 C/R. I am not sure what the problem is and I am about 50/50 on whether it is the computer or the program. I am going to do a virus check just in case. The whole system has been operating nicely with just a few moments of grief which we all probably run into, but this is a real head scratcher.
 
Any thoughts, suggestions, medications?
Thanks!

Turning off plug-ins does not remove them from memory. But most effects do not use much memory in the first place. Freezing tracks, bouncing and archiving tracks will reduce memory and CPU load. Hard to say what would cause an "out of memory" condition with the information provided in the post. There could be a problem with the memory chips themselves.

One more thing, how large is the cwp file?

I will check my ram and see if there is an issue. I have done the freezing, bouncing, and archiving to reduce the load and no joy there. Thanks for the tip. What information would be helpful in assessing the situation? I am glad to provide...

.cwp file is 2.81 mb
I did notice that a week ago that file was 1.53mb...hmmm 

The project file is not too big but a recent doubling might be of interest. Projects can get bloated with audiosnap data (a tool mentioned in the first post) which as been a problem in the past. But I doubt this is the problem given a 3MB project. If this is the same project mentioned in another thread, this is a work in progress spanning multiple years. Is is a mix of 32bit and 64bit plug-ins? All we have been told is has 32 tracks with goodies on it. Since tracks are frozen, bounced and archived is the project all audio now?

The project is all audio now and no, I have never mentioned it before as it has always behaved in the past - did a memory check and that is good - no errors. I will check the differences in the files for a sign of bloat. Where do all the edits go when you turn the program off? Is there a black hole they all get dumped to and fester? 
 
I do want to say that I am very happy with the setup I have on the whole. I do not have the raging disappointment that some have about the integration between software and hardware.

If the project is all audio and there are no problems with the hardware (might want to check the windows event log) and new projects do not fail with the same error, it may be a corrupted project file. Rebuild the project starting with a fresh project file.

Thanks scook! I will give it a go. Back with an update later tomorrow.

Running out of memory problem that is solved only by a reboot suggests a problem with reallocating memory aka memory leak. You are running the 64 bit version of Sonar? When and from what program are you getting an error message that says you are "out of memory?" What  is windows resource monitor showing when this error occurs?
 
http://www.pcworld.com/article/241677/how_to_use_resource_monitor.html