Right, I checked this out thoroughly.

The fault seems to lie with the MP3s themselves. Because they are not tagged correctly if at all it's causing the database to throw a wobbler.

So, it seems that it's quite important to have the MP3s tagged correctly in the first instance.

I've gotten around the problem by adding the albums with the Amazon lookup and all is well.

So far i've logged 3915 disks and counting. Another 3,000 or so to go