Both me and Whitlock Dunbar are suffering from this problem too - see this thread
http://forums.creativecow.net/readpost/2/932685
Rather worrying and annoying really. I've tried importing many different .movs which I've had no problem importing in the past and which open up fine in Quicktime to no avail.
Also as a side note it still says '.mov' in the drop down list in the import dialogue window as an acceptable file.
Hmmmmm, how frustrating!