Playing .mov files on iPhone

I've got a brand-new iPhone 3G, and have downloaded a podcast from iTunes. It's a .mov file (quicktime). I get a message that it can't be synched to my phone because it's not in the correct format. I'd expect the Apple phone to be able to play the Apple Quicktime file from iTunes right away, but ok -- I try using the "convert selection for iPod/iPhone" feature, but get "Error occurred while converting the file 'bla'. The required file cannot be found." This seems to be the case with all .mov files - even if downloaded through iTunes.

Can anyone shed some light on this? Thanks!