I've been hearing of quite a few issues with the code checking your inventory size. I'll take a look. I think your best bet until I get a fix out would be to save and quit once you are again under capacity (maybe give it a little extra room) then try to stay under the limit. I'll do my best to get the next version out as soon as I can, but I'm still working through the bugs backlog on top of a quest overhaul.