Pixma MP780 scanning problems

I have an iMac G5 and a Canon Pixma MP780, and everything works except the scanning. Well, actually it will scan perfectly well with Apple's Image Capture, but Canon's MP Navigator and Omnipage SE will not scan. They both try to open Scangear Starter which fails to open a driver (according to the error message in MP Navigator). When I try to open Scangear Starter on its own, it tries to open and then immediately closes. Canon tech support have absolutely no idea why there software won't work. Does anyone else have the same problem with Scangear Starter not working? Is is just bad software, or is there a conflict with another piece of software stopping it from opening?

Any help would be much appreciated.

Same problem

I have exactly the same problem, but with a MacBook Pro. Guessing it's the software. I see this is kind of an old post. Did you ever figure out a solution?