I noticed in my XP Host when virutalizing Fedora, and run some updates from the Fedora Guest ... all the XP Host seems to freeze... I do have 1GB in the Host.. and the Guest supposed to use only 256MB.
But long story short, seems like when the Guest uses a lot of network resources send the cpu of the Windows Host to 100% CPU utilization...
Maybe fixed in future releases just want to give the heads up....
Dinooz