Carlo Costanzo from VMwareInfo.com has posted the following helpful article:

The SVGA II driver installed by VMware Tools doesn’t work with 2008 R2 or Windows 7.  Console sessions will randomly lockup.

http://communities.vmware.com/thread/218244?start=105&tstart=0

According to the thread there is a WDDM driver in U1 that you can install manually to fix the problem by browsing to -

“C:\Program Files\Common Files\VMware\Drivers\wddm_video“

A good one