Just a note folks, the hpHosts server just died with a BSOD (STOP c0000218). It's in the process of dumping physical memory to disk, and once it's finished, I'll begin diagnostics.
CHKDSK and defrag have finished, as has the analysis, and sadly, CHKDSK revealed bad blocks on the main system drive. I'm going to get the drive replaced as soon as I can (likely not going to be until next week however), and will be monitoring it closely until it's done.
Sorry for the interruption folks.