This has become a nightmare. If anyone has had similar issues, and has found a way to fix it, please post. Here's the latest on my saga:

Yesterday I spent nearly an hour and a half on the phone with a Delta agent. We tried the same thing we did the day before, to no avail. Then she called IT and had me wipe my password "clean" -- i.e., clear my password and all security questions -- then had me try to resent my password. All went well until it came to the point where I was supposed to login using the new password. Again, I got the same "Uh-oh!" message I've been getting for the last several days. The best the agent or IT Department could do was to tell me to wait and try again today. I just tried - same result.

Grrr.