I have two Sony DVMCs, a DA1 and a DA2. As has been reported here, iMovie 05 does not work with the DA1. It does work with the DA2. Both work fine in iMovie 04. If you try to reinstall iMovie 04, it will complain that a newer version is already present. Here's how to fix that.
Open your Applications folder. Drag iMovie HD to your desktop.
Open /Library/Receipts/. Remove all the iMovie files.
Install iMovie from your iMovie 04 CD/DVD.
Run Software Update to update iMovie 04, if needed.
Drag iMovie HD back into your Applications folder.
And that should do the trick. You can only run one copy of iMovie at a time, and double-clicking old iMovie files will probably cause iMovie 05 to launch, but you should be able to capture from your old DV bridge with iMovie 04 just fine. I've already done this procedure on a graphite 733 and a Mini and it worked fine in both cases.