Hi,
I am also facing the same issue.
My setup:
Host System: OSX 10.8.2 running on MBP Retina + VM Fusion 5.0.2
Guest System: Win 7 64-bit
Scenario: I have a XAMPP installation on Windows with Tortoise SVN installed. I use Textmate in OSX to do the development using shared folders (I use the tree browser functionality in TextMate).
Problem: The system keeps hanging every now and then for a few seconds, specially when switching from the guest system to the host system. It hangs everytime going from Windows to Textmate in OSX, but this hang lasts only a max of 2 seconds as opposed to several seconds for other hangs.
Piyush