I'm using Mediatomb on a 10.4 OSX PPC Mac. In general, it scans new content very quickly, less than a second for a full album of mp3s. However, certain tracks take 2-3 minutes to scan just one.
I've tried looking for something in common between the files that take forever, but I'm afraid I don't know enough about how these things work to figure it out. :(
You mean some mp3 files take that long? Strange indeed… scanning is done with the help of various libraries, for mp3 we use either id3lib or taglib. Would be good to try to read metadata from those files using id3lib or taglib command line tools and check if the problem is reproducible there too. If yes - that'd be a problem in these libraries, which I assume is the case.