hi all, (i'm reposting this thread from "mac basics") i have the latest version of itunes running on the latest version of snow leopard on a reasonably decent late 2007 intel imac core 2 duo. i even just upgraded the ram to 4gb and everything. oh, and i just reinstalled itunes to try and combat this problem but it still happens. however, i have a big problem with the latest version of itunes (this might have happened previously, i am just only now using itunes for videos in a big way since just buying an appleTV). basically, what happens is this: imported .m4v videos edited with MKVTools transfer in okay and can even stream onto the appleTV however, if i try to change tag information for them, itunes freezes indefinitely and i have to force quit it. reopening itunes takes AGES on the "checking itunes library" stage i can now change the tag info fine, but the file is permanently corrupted - unable to play on the appleTV, itunes or even VLC. i can't even get any useful streams out of it from MKVTools. obviously this is infuriating for the files i've lost already, but it's most annoying going forwards. i want to build up a library of movies, but don't want them to be all tagged incorrectly etc. oh, and this issue doesn't appear to happen with .mp4s converted with handbrake, by the way. help appreciated!