'No Data Transfered'...?

Over the last week (maybe two - at least since the major down) I've noticed a message thats seems new, at least more than 2/3rds of the competed work units I try to upload are imidiatly followed with 'No data transfered' straight after the finished upload message.
This I'm finding worrying cos i get the idea that the results probly arn't being sent/recieved and i know its not a problem with my computer or connection because i get the same message on 2 totally seperate machines and connections.
Also there is no option to resend these results.

What does this actualy mean? is anybody else getting this? and should I be worried either that seti isnt getting them or I won't get credit?

Please tell me i havent found a new fault with boinc.