I'm experiencing the same problem stated in the original post.
My confirguration = Host Windows 7 x64
= Guest Windows Server 2008 R2
= Both OS are with latest SP and are up-to-date with Windows updates.
= Workstation 9.
I have tried all solutions recommended above to no avail. Please help.
p.s The only comfort I got so far is knowing that I'm not alone in this boat.