Sometimes the Finder gets a little confused about which icon to display for certain file types. You can fix individual files by opening their get info dialogs, selecting the icon and hitting delete. The only way to fix all files that I know of is clearing the icon cache - there are programs out there designed for just this purpose, though I don't know the names of any.
I've got exactly the same problem. I can't figure a way to fix it. I re-installed them all using candybar, but they're not being recognised. I;ve tried a relauchn finder, and a restart, but it won't help. not sure what else to try. Is there a way to uninstall the update?
I'd also say that the speed of loading files in quicktime has decreased, I've got 2GB ram in my Macbook, and they used to open after a few seconds tops. Now, they're taking 15 seconds plus.
I've got the same problem. I suppose it's not even a problem, per se, since the files still work fine. It is a nuisance, though. Did this happen to everyone? Is there a way to fix this without reverting to an old version of QT?
[Edit: Also, I have a rather hard time believing that these eight posts are the only information/discussion regarding this little problem. wtf.]
Not having that problem here, closest thing I have to that is that my MKVs only show up as VLC files, instead of Quicktime as I prefer (Like to have all my video playable in Quicktime, since that also means playable in Front Row)