Hope this is not considered a hijack, but no solution was posted here.
My site has just been bitten with the same problem.
Here's the scenario leading up:
Two nights ago, I get an email from my web hosting service saying my domain has just been created, then a second saying my client account had been created. 33 hours later I get this:
"The validity period of the client account 'whitney1' has expired. The client account and all related domains were deactivated on Sun Sep 13 2009."
It appears to me the web hosting service moved my database to a new server. I have not requested anything from them for many months, so all of this action was initiated by them. (I'll be calling them Monday morning to inquire.)
However, the forum, which is running v7.1, has just acquired these symptoms described above. And in addition, when I click on a thread title, where the Firefox URL ends in #UNREAD, it goes to the first post, and NOT the unread posts at the bottom. In fact, there is no id=UNREAD tag in the posts displayed.
I have tried the Control Panel "Clear Cache" option, as well as within Firefox, Tools, Options, Privacy, "remove individual cookies", located my website, and clicked "remove cookie" on all five cookies for the web site. But I still have the problem. Users
are complaining as well.
I do hope there is a simple solution to this.
...I'll post more info after I talk with the hosting service people.