Document contains no data: common causes?

[segdeha]

I wrote a little application that works fine when run locally, but gives the error "Document contains no data" when I try to use it from our development server.

My local server is running PHP 4.3.4 and the development server PHP 4.3.3, but this shouldn't be enough of a diff to cause this kind of error, right?

I've read about ereg() and IMAP configuration as possible causes. I don't use ereg() (or any of its cousins) in this application and I have to admit I don't quite understand IMAP and why it would cause this.

What are common causes for this error? Are there particular coding practices that often lead to this situation? Are there particular configuration choices that make this more likely?

Thanks in advance for any help!

[segdeha]

Looks like the problem has to do with how I'm handling sessions. For some reason, my session variables are not persisting past one click through the application.

Any ideas?