every now and then, the following things stop working on my server (all at the same time) until i reboot:

ftp, ssh & login to directadmin control panel
website session ids (i use these instead of cookies)

apache still works fine, my websites show, but you cant click through the pages on my sites as the session id doesnt work.

It seems to happen randomly, I cant tie it down to a specific time period, or after I have done something to the server. It never seems to happen straight after a reboot though, always after a month or two.

I believe the problem must be entirely to do with usernames / passwords.

the php session ids are created by the apache user account. so just like when I cant ftp & ssh in because my passwords are rejected, presumably apache cant create a session id because its username or password is not accepted by the system.

does this sound right? does it help narrow it down to a possible cause?

i wish I knew more about linux but ive been using windows solely for years.

im running on debian 3.1.

any advice, things to check, possible causes etc.. would be greatly appreciated!

Tom