On the chance that this might help someone doing a search for for why TI is hanging/crashing on them, I'll pass along how I [hope] I solved my problem. I'm using TI 9.0 build 3854, and XP Pro. Over the last year or so TI has saved my butt more than a few times since I do a nightly backup of my C: drive and if something goes wrong with an install, etc. it's been just easier to reimage the drive than to spend hours fixing the new problem. (I keep email, IE Favorites, and other often changed files on another drive, so the C: drive isn't loaded with files that change hourly.) Anyway, lately TI has been hanging when I tried to do my usual differential backup. The program would start, get to about 3%, my mouse would lock up, the clock would quit adding time, and the whole computer would just stall. I'd have to restart. There were never any errors in the Events log, or the TI log. Today I noticed that one of my regular start-up programs - WinPatrol 11.3.2007.0 - was showing a different version of its usual icon in the taskbar (white eyeball on Scotty dog) when TI stalled. On a hunch, I exited WinPatrol and tried TI again. This time TI worked just fine. Problem solved. I think. Over the next few days I'll monitor TI, and probably stop using WinPatrol, or at least quit that program when I run TI. I'll be curious whether anyone else posts that WinPatrol was causing the trouble. The version of WP I mentioned is reasonably new, so I may try to find an older version since I'd never had any problems before. Hope this helps someone.