After upgrading from v2.5 to v4, when I repeatedly suspend and resume WinXP it tends to crash. I found this thread: http://forum.parallels.com/showthread.php?t=32295&highlight=suspend+resume I did find some mem and sav files and deleted them. This improved the situation and I was able to suspend and resume much more quickly... at first. With the mem and sav file present, it would crash after about 3 times. After I deleted them, seems like it took 5 or 6 times. Every time I suspended WinXP, it took a little longer, then much longer. It seemed to be taking a snapshot of a snapshot, where v2.5 simply saved the state? When I suspend the guest OS, I also sleep the Mac (running Tiger) overnight. In the morning is when I see the symptoms. All of my guest OS applications appear to load and run fine. But, when I click on the "File-Open->" button on an application, then it stops responding. It seems to be related to the common controls dialog. Mind you, it works fine if I never suspend. I have been bypassing the problem by starting the OS in "Safe Mode", letting it boot up each time. This way, I can just hit "stop" and discard the disk writes back to the disk rather than going thru the entire shut-down sequence. It would be nicer if I could suspend and resume. I hope someone is looking into this for v5.