[overhead]

Thanks for the replies folks - I'm using a programme called FolderMatch,following vht's suggestion of getting the P.C to do the work for me,which is helping a great deal.
I've located a few thumbs and the odd text file or picture which for some reason don't exist in both copies.I haven't licked the folder situation yet,but it's narrowed down the number of mismatched artist folders from 358 to 76,and for most of those,the only difference is the date the folder was created,which I guess happened when I outgrew a hardrive and got a bigger one to contain everything.
We're getting there!Thanks all!