while your approach helped you the connection does not appear to be the solution.
i have replaced the backup drive, USB cables and the USB plugs in the computer.
I also note that the old drive works perfectly on windows machines as I passed it on to a co-worker.
the old cables also appear to work perfectly as they were passed on too!
I also note that this happens on both my iMac and my Mac book pro!
so to sum it up:
1. new hard drive in computer - still problem!
2. new back-up drive - still problem!
3. new cables - still problem!
4. new USB plugs in Computer - still problem!
5. connecting thru firewire plug - still problem!
6. service center - for check up - they gave up! still problem!
7. reloaded OS numerous times - still problem!
I am convinced that it seems to be a OSX problem.
I also note that I contacted Apple and they said they never heard of this problem. Hmmm!
Maybe there was more than one reason that Scott Forrestal, who developed time machine and the maps application was fired.
Yes, I am mad about this. been going on for about 4 years now. sometimes it will go for days without ejecting, then sometimes it will eject 5-6 times in a session.
i am glad you seem to have had an improvment, but believe it or not the problem will still exist.
Norm