undo line numbers wrong

[Robert Cussons]

Hi all,

just wondering if anyone else had experienced an error message like 
this. It seems that every so often, I've not managed to find any 
systematics to this, when I try to perform an undo, I get "undo line 
numbers wrong" or something similar, sorry I don't have the exact error 
in front of me, it happened about 5 minutes ago and I was in the middle 
of something, so I just dealt with it! It doesn't happen very often, but 
when it does if I later try to undo something, it all goes a bit haywire 
 and seems to not undo the last change etc. Sorry this is so vague, if 
it happens again, I'll see if I can pin it down better. Just wondered if 
anyone else had experienced this and maybe knew the cause.

Thanks in advance,
Rob.