Got it figured... on the last update, it changed (at least) one of my settings telling Seti to reserve all of my HDD space for other use - it had been set to allow it 75% usage, 25% reserved - When I looked at my available disks space at My Computer, I misread the Pie Graph exactly oppositely since Seti was showing it's graph as HDD full - I assumed my HDD was full. Very far from it, less than 22GB used
lol, also explains the (non-existant) hidden files I was seeking out and why I couldn't figure what had eaten up my disk space - Doh!