"backup limited to 10.0 MB"

I have had the same problem like you due to a rather large MySQL database. Therefore the MLF internal backup procedure (admin area) failed every time. In my case this was a file size limitation set from my hoster. So I asked him for a higher value (64 MBytes) and some houres later the backup procedure reaches without any error the end and results in a 45 MByte complete backup file. Perhaps you should change your hoster, the little or medium one are commonly more flexible in solving such problems as the big players.