Aperture com.apple.qtkits deny

Question

When I launch Aperture it grinds to a veritable hault.  Looking in the console reveals thousands of messages piling up.  These messages all take the form:
1/25/13 4:34:43.475 PM sandboxd[40351]: ([40349]) com.apple.qtkits(40349) deny file-search /
1/25/13 4:34:43.483 PM sandboxd[40351]: ([40349]) com.apple.qtkits(40349) deny file-read-data /
1/25/13 4:34:45.753 PM sandboxd[40351]: ([40349]) com.apple.qtkits(40349) deny system-fsctl 0x7a0c
Clearly the sandbox is preventing Aperture from doing what it's supposed to do (the purpose of the sandbox, ironically - but that's another topic).
I am using the latest versions of both (Mac OS X 10.8.2 and Aperture 3.4.3).  Nothing is pirated; I own both.
Anyone have any idea how to go about fixing this, so I can use Aperture again?  I am reluctant to do the whole PC "delete and reinstall" business, but I am more than happy to dig around the Library folder and edit or delete plist files.
Thanks for any tips.

Answer 1

Even if that would help (and thanks for getting me this far), I'd rather not permanently disable video previews.  I've been using iPhoto instead of Aperture while this gets fixed, and Yet despite waiting the last upgrades of Aperture and Mac OS X neither have fixed the bug.
Perhaps there is some way of forcing some kind of a reload of video, or of changing permissions for those actual files?
The menu command as it turns out is "Relocate Original" which lets me "move" all files into the Aperture library's Storage in the file system.  Because my Library is not a "Managed" library, the library file itself is on my Mac, while the photo/video files are all on the Time Capsule.