Flex Builder 3 on Eclipse 3.5 (Gallileo) on OS X?

I spent a little time this morning trying to get FlexBuilder 3 up and running in Eclipse 3.5 (Gallileo). A little experimentation and reading implied that getting it up in the Cocoa version of Eclipse wasn't going to happen.

I then tried a few more times with Eclipse 3.5 carbon, and still wasn't able to get it working. So if you've managed to get FlexBuilder 3.X up and running on Eclipse 3.5 on OS X, I'd be happy to hear more.