[Irl]

Full history:
While starting up, started an application (Amadeus Pro) which tries to allocate a large scratch memory area. (This may be irrelevant.) System hung, Finder didn't start. Tried quitting the Finder, didn't help. Deleted all of my "login items" in the hope that something there was causing the problem; didn't help. Started TechToolPro, couldn't unmount either system or user volume (files were allegedly open). Rebooted from the eDisk which TTP sets up, still couldn't unmount. Used TTP to "fix files" (couldn't "fix volume" since that requires unmounting), that made the system volume unmountable. Unmounted it, ran "repair permissions" from Disk Utility, noticed that one Finder-related file (I believe it was its .plist file) was listed as having wrong permissions which was then fixed. At that point the system would start up normally. I had foolishly neglected to make a list of my startup items so I restored the ones I remembered or was reminded of by perusing the list of installed applications.
After all of that, the problem with SD appeared. I noticed it because the overnightly backups failed to run the night after the disaster recovery, so I tried running manually, with the failure I reported in my original post. These normally run from an account which does not have admin privileges (my non-computer-geek wife stays logged in overnight). Note that I can run a backup (while logged in as her) from the main window, just not the "scheduled backups" one; thus scheduled backups don't run either.
Is there a process important to SD which I could verify is running normally in the Activity Monitor?