I do the "Mileage Work" for my family, and that means I check 4 accounts. 3 accounts have all letters as passwords, mine has all numbers (I am also a PremEx, everyone else in my family is a member, no status).
My guess, either UAL.com went to case sensitive (and I have no idea how I typed in the poasswords "casewise" the first time), or they are puttinbg accounts back up by status.
NOTE : The reason I said my password was numbers was because numbers cannot be case sensitive, so I would always be able to log in.