Well, it didn't seem to last 3 hours. Although, I sure know my user name and password!! I guess that's a good thing??
You would have had to re-sign in today after 11 AM CST.
The changes I made expired all older cookies, so coming back to the site today from earlier (say 10am) would have expired your login that you saved/did at 10am.
But logging in again now, after 11 AM CST - not just re-visiting, I'm hoping I have nailed it.
I was able to re-produce the issue at any time (i.e. restart the app pool, the Ticket (cookie) would be invalid). After my applied fix this morning to a few select domains on my server (this is one), I was able to remain logged in after restarting the app pool.
So I think I nailed it. But, only time will tale. :)