My admin account was disabled recently, too. I fixed it by altering the gl_users table, as you mentioned above. It happened when I was trying to add other users for the first time. I was having trouble because I could not add users from the Admin Users section, because it said the password did not match the confirmation password, even though there is only one field. Then I hit the login speed limit, and then my Admin is Disabled.

hmmmmm

Right. I think I figured it out, a hit the forum a bit quickly. The errors stemmed from my theme, which specifically did not have correct password fields for new users and admin user pages. Copying the correct myTheme/admin/user and myTheme/user pages from the 1.4 Professional theme did the trick.