Sorry for getting back with this question so late. Turns out the solution was to talk to the network guys who had blocked certain file types of video online from playing. It's all working now.
Thanks for all the input, I definitly know how to re-install Quicktime and how to verify installation lol.
So the solution for anyone else with this issue might be to check with your network admin if you are on a network. (which I think I failed to mention!) =/
peace,
zbox