phpBB Login bug

At a forum that I mod for, we have a problem that mystifies us. It has several symptoms:

1. Users automatically logged off whenever they leave the page, even if they have "automatically log me in" checked
2. You have to log in twice in order to actually log in.
3. When you manage to log in, all the recent posts, even the ones that you have not read, are set as read

The only workaround is to log in through the private messages link. One more piece of info is that we have a phpNuke board also, it uses a different database, but these problems did not surface until after phpNuke was installed.

 

In the admin options check the options page (I think general), and make sure the address for the cookie is correct.

A friend's was set thealternativesport.com, when it should have www.thealternativesport.com, which caused the same problem.