For the benefit of the JAMF community, I am sharing a recent troubleshooting experience.
I was unable to get Flip4Mac to load in any web browser after imaging a Mac using Casper Imaging. The following error message appeared in the logs as it attempted to load the wmv file:
Failed to communicate with qtkitserver: Connection invalid
When I built the core OS image with Casper Composer, I had selected the option to clear caches, not thinking twice about it. Apparently, there is a bug in Mountain Lion that prevents the com.apple.xpchelper.cache file from automatically recreating. This file is normally located in /System/Library/Caches.
The solution is to force the file to be rebuilt, and restart the Mac. Use the following command:
sudo /usr/libexec/xpchelper --rebuild-cache
According to my research, this can fix a bunch of media plug-in issues, including issues with Aperture and iPhoto. That file is somehow critical. That file is most likely deleted by any utility that clears System caches.
I hope this helps save someone else some time, as I spent nearly a week tracking this issue down!