Steegy, apparently there's been some code changes in the Discogs layout. There are example scripts at Mp3tag
that supposedly fix the problems, but they are incompatible with the current installment of Web Sources Tagger. I tried to copy/paste segments to make a script for WST but that didn't work; I can't claim to know much at all about the scripting system used.
Are you planning to release any further updates to Web Sources Tagger? It really sucks not being able to use it, that application was the best one I have found