Installed Parallels 6 on iMac OSX 10.6.5 - No longer able to switch to Coherence Mode - Worked in Parallels 5 as my normal/standard Mode. Get error message - "The amount of video memory set for this virtual machine is too low. Increase the amount and try again." Checked configuration - Memory is already set to 1072 MB, high end of Recommended. ????