I noticed some of the slowdowns mentioned in other posts here yesterday, which on my machine are quite rare. The main culprits I've tracked down are either processes that take host or guest disk i/o or cpu time (like spotlight). Most recently I noticed that imapi.sys process was eating cpu cycles in the xp-64 vm while the responsiveness was seriously compromised. I killed imapi and disabled its restart using autoruns (imapi.sys and imapi.exe) and the VM resumed its fast responses despite several sleep/resume cycles. Hope this helps other users or updates...
MS
