Disregard the thread guys
I screwed up is why there was only one file. I'd tried initially to move the entire folder to an external PS3 disc with cut paste, at which point I found out that a file was over 4GB and after investigating as I described, I decided to put the file on the internal HDD
The initial cut paste however, moved everything else that was < 4GB, leaving just the one file in the original location....
Too much time went by in between - even upgraded the internal HDD of the PS3
I totally forgot about that failed cut paste operation
Thanks for your help