This is not just an XP issue. I had this happen on a 7 install. Something like this is inexcusable for a security program, as many people aren't even going to notice and are going to be left unprotected. But considering the poor programming I've seen from MWB and the complete lack of interest in fixing it when pointed out, I'm not at all surprised to see this happen. MWB is great at what it does at the core, but it has some really lousy framework surrounding that core.
And as a side note: two separate anti-bot checks to register for these forums is ridiculous, just pick one.