session ids dropped on linux using phplib but works on windows

[trube]

I have an app I wrote that worked fine before both on windows and linux. But I just installed the latest version on linux and I can't login. The exact same code works on Windows. After trying to debug the darn thing all day long, I realized that on the linux server the session ids are different on each page.

So let's say I go to the login form. I get session id #1. Then when I submit the form. The next page has session id #2. Different session ids. 🙁 So the server thinks it's a different person each time and it never checks to see whether the username and password are valid.

When I use the same code on my windows development machine, the session ids are the same page to page. Login works.

My old versions of the app works still works on the same linux machine. Session works there. So I don't think it's something to do with the installation of PHP on the server.

Registered globals is off.

I'm using phplib, the version with PHP4 sessions.

Any ideas? I'm about to yank out some hair.

[trube]

Okay, after over a whole day of debugging. I solved it. Hopefully this will save some people trouble in the future.

The session ids didn't carry through because I had an underscore in the subdomain! I had installed the new version of the software under this subdomain:

ver2_beta.domainname.com

Well, the underscore screwed it up.

It all worked when I changed it to:

ver2.domainname.com

So, never put underscores in domain names.