Okay, I really don't understand this! It's happened to me twice in the last 2 days. Attempting to login as an administrator or as a user, I enter my login info, and Drupal shows that particular username as being online, but the login boxes reappear and keep coming back no matter what username or password I use. If you attempt to login more than once, Drupal shows multiple instances of the same username as being online. I can't access my administer functions, and none of my users can get into their accounts either.

Drupal 6.14
godaddy hosting
PHP5.x

Interestingly enough, I can fix it in a roundabout manner by copying in a new settings.php from the downloaded 6.14 installation files (a fresh copy of default.settings.php), going to drupal/install.php, entering my database name, etc., and when it tells me there is an existing installation I just hit 'see existing site' or whatever and voila! it works again. That seems horribly inefficient and error prone to me. I've tried truncating my cache tables, quite a few of the patches, etc. out there, clearing my cookies, history, cache, etc. but nothing seems to work except this rather drastic measure.

I've researched this online for many hours now but it seems that all the info out there is for Drupal 4 and 5.

Please help me understand! I don't want to have to do this again.