I'm looking for a similar thing, though I get a small message top right telling me something is interrupting the program - or something like that.
Being in W7 might give that, where XP doesn't.
Best guess at the moment is the external hard drive I'm plugging in on a USB connection about half the time. It may be trying to access that while it's spooled down, but be alright when it's either running or not plugged in.
Because it's intermittent in any configuration, I'm still not sure of my facts.