Well, I have the replacement issue (#8) and when I first saw it I'd have to say I thought the offending gear looked pretty similar to the first one.
I tried it anyway and what d'ya know - no difference. However, at least this way I only had to wait 5 days to find out instead of the 2 months the newsagent originally told me
Wel, I decided to try and solve the issue as I'd still really like to have a completed model. So basically I set about filing the offending gear wheel down in terms of tooth length and thickness. It was a bit of a pain to do, but each time I re-tried it, it went a bit further around the large gear, until eventually the earth/moon gear moves effortlessly all the way around.
So I'm a happy little vegemite now.
Cheers