Thanks for the heads up.
The battery has been disconnected before and there's never been an issue - so I'm just as surprised. I'm almost wondering if there was form of static discharge as the battery was changed or something really daft like the replacement went in backwards for a split second - though I suspect that would have done much more serious damage!! The beemers are supposed to 'self-recover'.
That being said, my E53 just came back from having it's transmission repaired and it had lost the remote locking capability from one of the keys. It had a dead vehicle battery too. Remote locking on all keys fixed now thanks to this site - you folks rock
The latest try is to fit an OEM battery on the E46 in case that works - I can't see what difference that's going to make, but if it works.........
We'll get that fuse tracked down too. It's not listed on the fuse card and I never thought to look - mind you it means taking half the boot trim out to get at it unlike the 'X's little rack.
EDIT - Perfect. That was the little beggar. Not listed on the fuse card, nor known by the indy dealer. Spot on. The only mystery now is why all this happened when all they were supposed to have done was take one battery out and put a new one in. I don't suppose we'll ever know now. Thanks again. The membership scores another 100% success story.