There is a new updated version of Snow Leopard out. If you have one of those new 2011 MacBook Pro's with the Intel HD graphics who have been having problems, this should resolve the issue.
"The 10.6.7 Update is recommended for all users running Mac OS X Snow Leopard and includes general operating system fixes that enhance the stability, compatibility, and security of your Mac, including fixes that:
- Improve the reliability of Back to My Mac
- Resolve an issue when transferring files to certain SMB servers
- Address various minor Mac App Store bugs
For detailed information on this update, please visit this website: http://support.apple.com/kb/HT4472.
For information on the security content of this update, please visit: http://support.apple.com/kb/HT1222."