still losing session userdata across a redirect

I don't think anyone else has mentioned it, but I've learned that there can be problems with the order that you set session data and do the redirect. I always set the redirect before writing to the session. I've had problems changing that order in the 

I don't really understand. But ill try it.

I don't really understand the reason either, but it has made a difference for me when doing redirects and dealing with sessions.

Can you elaborate and/or show examples of this where it does/doesn't work?
It's not something that should make a difference. If anything, doing a redirect before altering session vars could discard those changes to the session.