I can confirm this behavior with FMP 10 adv. It comes and goes which makes it difficult to reproduce.
Using Windows XP and FMP 10 adv.
I can confirm this as well, and the problem seems to be with FMP(a) 10, because it happened to me while working on a solution hosted by FMS 9.
Several colleagues of mine have made mention of the issue as well. I worked for some time trying to find what actions would reproduce the problem, but could not nail it down. So good luck getting this one fixed ... hard to fix a bug that cannot be reliably reproduced.
Anybody see this happen on the Mac side of the fence or is it strictly an XP issue?