They say one of the big advances with Auctioner Advanced is that the code itself is a lot more memory friendly and it also loads in pieces so that it's not always taking up maximum memory.  I haven't noticed a problem with it at all, though I haven't checked the numbers to see what kind of memory it actually uses.  I never had a huge problem with Auctioneer before though, I had it set to only run when I opened the AH window.

The signature server must've been down for a short while because it's working again.  It seems to go down often for somewhat short durations.  /sigh