So I made the first of my readiness upgrades for Vista today: I installed a second 1 gig DIMM of RAM in my machine...same brand and speed as the existing DIMM, lo and behold the memory test in Vista actually dropped 2/10ths of a point, from 4.2 to 4.0 (~5% decrease).  I wasn't expecting it to go up, but certainly wasn't expecting it to go down.  What gives?  Could the new stick have some faults in it?