Custom page throwing: Unable to add cookies, header already sent

[kh99]

You may know this already, but "Unable to add cookies, header already sent" I think means that something was written out before the vB code tried to set the headers, and if you don't have any code before the global.php include, then it's probably a warning or error message.

I know you said your problem is happening at a shorter interval than the session timeout, but just FYI, I believe the session "last activity" time is set on most vb pages by the call to "print_output" at the end, which I guess you're not calling in your custom page.