User credentials change automagically

Ok, this is bizarre.

Our IT group uses RT for problem tracking. There are only 4 accounts
(kept in RT), one for each of the 3 real people and one called “root”
(for admin functions of RT itself). We’ve been using RT 3.8.8 since
November - the problem I will describe just began happening this week.

2 of us are logged into RT pretty much 24/7
I use Firefox 4. Never have a problem
User2 uses Opera 11. RT itself works fine for him.

Neither of us knows the other’s password…

Problem:
User2 locks his computer and goes to lunch. When he gets back from
lunch, his RT session is somehow magically logged in as ME.
Huh? How could that happen?

It gets even more bizarre - if he logs out of RT on his computer, the RT
session on my computer gets logged off ???

What’s going on here?

Chris Barnes AOL IM: CNBarnes
chris-barnes@tamu.edu Yahoo IM: chrisnbarnes
Computer Systems Manager MSN IM: chris@txbarnes.com
Department of Physics ph: 979-845-1379
Texas A&M University fax: 979-845-2590

Ok, this is bizarre.
[snip]
Problem:
User2 locks his computer and goes to lunch. When he gets back from
lunch, his RT session is somehow magically logged in as ME.
Huh? How could that happen?

It gets even more bizarre - if he logs out of RT on his computer, the RT
session on my computer gets logged off ???

What’s going on here?

We’re talking to your coworker Joe on #rt right now about your problem.
To summarize, we’ve never seen a report of this which wasn’t the fault
of a caching proxy or mod_cache in Apache screwing up. Basically
cookies get improperly cached and sent to your browser, which makes you
logged in with another user’s session.

Thomas