When I have previously blacklisted members they have been unable to buy from me (and also me from them) - as expected.  Just realised I made a purchase from a seller 2 weeks ago that I already had on my blacklist - they have mucked me round exactly as per last-time and sadly I did not remember their username (otherwise I wouldn't have purchased) and no blacklist warning came up.  Have just tried to purchase from them again (as an experiment) and it seems nothing is stopping me.  Is there a glitch in my system, I thought it worked both ways (buying AND selling) but maybe I'm wrong?  Item has...