Floating square of Windows desktop appears in Coherence mode in 9310

Hi, I have a problem with a floating piece of the Windows desktop appearing in Coherence mode in build 9310 (the latest as far as I can tell). This has only started happening since I upgraded to Parallels Desktop 5. I tried reinstalling Parallels Tools to no avail. It's a fairly vanilla Windows XP install, I use it primarily for testing IE and occasionally running a few Windows apps. I saw some other posts on the subject from quite a while ago, for Parallels Desktop 4, but I didn't see any resolution, so I'm starting a new thread here.

 

Floating square

Yes, I newly installed Parallels and discovered this also.

Although suspending (not closing) the Virtual Engine then starting it again, seems to get rid of it.

 

Update

....except after the latest upgrade this didn't work any more. But going into windows and setting the screen resolution to the same as the mac's screen has now apparently removed it.