I've got a similar problem. My EOS 20D isn't recognised either.
If I look in the EOS software on the computer it sees there is a 20D there, but any attempt to access it doesn't work. I use a card reader to get the pics off, but when plugged in OS X creates the recyle bins etc on the drive, so I always reformat it when I put it back in the camera.
I haven't been able to get my remote control software working, which is annoying as I used it on my old windows laptop no trouble.
iPhoto doesn't always work for me, and I don't really like it anyway.
I'd be interested to find out the solution (if any).