After upgrading to Parallels 5.0 with a Win7 VM, Quicktime 7 appears to be buggy. I should note that otherwise, my install went flawlessly and graphics performance is much improved. The machine in question is a 2008-generation iMac. Aero even works properly now. Also, on another 2006-generation MacBook Pro computer where I also installed Parallels 5.0, but running an XP SP3 VM, Quicktime works just fine. On the problem machine, streaming video (typically movie trailers from www.quicktime.com) play with only random, jig-saw patterns of the video available. The pattern is stable within the QT window; that is, moving the window around on the screen does not change the pattern of black pixels versus those that are visible. Audio is just fine. On the other hand, Windows Media Player has no issues at all, even at full screen resolutions, in keeping up with synchronized audio and video. I have uninstalled and reinstalled QT, and I am certainly running the latest version. The video configuration in both cases (Win7 VM and XP VM) has 128MB for video memory and 3D acceleration enabled, in other words, just the default configuration. If it becomes useful in this thread, I'll post a screenshot.
Quicktime performance impacted by video settings I continued to play around with this issue. First, I found that the same issue occurred in a Vista VM that was hosted on the same machine as the Win7 machine I had problems with. I suspected that there might not be enough video memory available, and so on a hunch I increased the video memory for this Vista VM from 128MB to 192MB. I found that this cured the problem for the Vista VM, with 3D acceleration enabled. For the Win7 VM, I tried the same thing. I discovered that I could not increase the video memory sufficiently to cure the problem. However, with 3D acceleration disabled and only 128MB of video memory, the QT problem was cured. I have attached a couple of screen shots from the Win7 VM. The first is with 128MB video memory and 3D acceleration on (note the Aero effects). The second is with 128MB video memory and 3D acceleration off. Both QT apps are running streaming video for the 480p HD trailer for "Despicable Me" from www.quicktime.com.
