I find it completely odd that FCP and FCE can't handle .mp4 video while iMovie crunches through it with no problem. I think probably, since most devices record to .mp4, the codec was designed more for viewing and not for editing.
I started my Live Music Journal video blog (http://livemusicjournal.blogspot.com) because I bought a Sanyo Xacti HD2 and couldn't edit the .mp4 files in FCP, so instead, I recorded full songs from live sets and didn't edit them at all. :) But still, it's a huge pet peeve that it works without a hitch in the consumer software while the pro software can't handle it. All that extra rendering makes it almost useless from a work-flow standpoint. Oh, and I've read that Final Cut Pro 6.0 can't edit .mp4 well, either. Bummer. Can we petition Apple to change that?
