Yes, I did re-try Odin, but it fails pretty early in the process. I've tried with and without the pit file, and I've re-downloaded both the pit and the stock rom just to be sure. Same result every time. I don't think it's the usb cable, since I used the same cable to flash to Froyo.
Interestingly, I did use the Home key to do the factory reset, and the phone came back up with no change in the data... ie all my contacts and everything were still there... not what I would call a real factory reset.
One other interesting item: I checked out the available storage on the phone: Internal phone storage has only 66.41MB of space available. This with only one installed app, which is the mandatory voicemail update. That seems very very low to me. I know it used to be upwards of 300MB.
I have a 90 minute break later today, so I'll try doing Odin, etc. all with a different computer then. Maybe that'll do the trick.
In the meantime, if any of you have seen this and have an idea what the problem is, I'd be forever grateful.