The probability that the problem you experiencing is the same is very low.
So here is what my little (and very annoying) google journey came up to:
- You must call session_start(); on each page
- If you use the header('Location: blabla'); you should use relative url to keep preserve session
- some people say before using the header action you need to call session_write_close(); - I'm not using it.
- session_write_close(); could be the reason to your problems, cause after calling it you can't modify the session (in the current http context), that was my problem.
- on php docs, they say that "Session ID is not passed with Location header even if session.use_trans_sid is enabled. It must by passed manually using SID constant."