quicktime codecs - Ubuntu 6.06.1

hi there
I've been trying to play different quicktime files in ubuntu 6.06.1 using totem (sorry, i'm a newbie- don't have too many specifics)
it basically says it doesn't have the codecs but when i check with the synaptic application, it shows that the libraries are installed.
i've been looking for different threads but i was unable to find more info.

to be more specific, i tried playing quicktime files from apple.com/trailers but since it asked for the codecs i figured it just couldn't play any quicktime files