I've installed mediatomb on an fresh ubuntu 9.10 system and start directory scan. After some time, they found some playlist files, generated from windows software which contains \ and not / in .mp3 file paths. It looks like, that mediatomb can't handle this and produce many errors which are written into the logfile. The logfile grows in an very short time so much, that the filesystem was full.
I've not inspected the problem more in detail, but I think, it should be reproduceable.