Quicktime Doesn't Work After Update

Hello. I just got the required security update awhile back, and since then I have not been able to view any thing using quicktime. I have changed my firewall settings, but I still just get a loading screen with a blue Q and then it freezes. Sometimes it ever freezes SL entirely for a while and then half of my mini map will turn red. I know that I have the latest version of quicktime, and my system more than meets the requirements to run SL. I generally have no issues with lag, and was able to run video just fine before the update. Just wondering if anyone has any ideas to fix this problem. I just rented a movie i really want to watch lol.
Thanks in advance, and sorry if I got this in the wrong thread =)

Is it possible to test this with QuickTime by itself, not as part of SL, by loading the parcel's URL into the QuickTime viewer directly?

One other suggestion, just because QuickTime regularly confuses itself for me: I'd try going to the QuickTime control panel, the Advanced tab, and click the "Clear Cache" button. This has occasionally let me get by without completely uninstalling and re-installing QuickTime.

(Oh, this is all assuming Windows. If a Mac or Linux, those are very different QuickTime environments to troubleshoot.)