WinXP SP3
PMV v3.71

Sometimes, often when copying a large selection to the clipboard (~4000x4000 pixels, 24-bit), the clock mouse cursor works as normal, but the clipboard is not populated with the data, and no error is displayed.

(Test: I open a 2nd instance of PMV and attempt to paste into a new image, but the Paste option is greyed out. Same for pasting into CS3.)

I am unable to find a reproducible sequence of steps to obtain this problem, but I have seen it intermittently and more than ten times. I reboot to clear the problem. I note it here in case others have the issue as well.