I go to the home page and I get the home breadcrumb. If I click page 2 I still get the home breadcrumb until I press F5 or click page 2 for a second time. Then when I click home I get the page 2 breadcrumb until I press F5 or home again.
Why isn't the session variable updating until I refresh?
Sorry for not following up, me and the wife decided to stay at a Casino and blow some cash as a late birthday get-a-way for her. :)
You should post the code on pastebin, or here if it's short enough. I just wrote a quick test and the variable should set after headers are sent and reflect the appropriate value with absolutely no problem, so there must be something else occurring that we don't know about.
Just a quick thought aside of the problem, why do you need $_SESSION if you set and read something on the same page ?
Since you could do this with any variable and $_SESSION is normally used to read something in, that you set on a previous page.