This report is regarding the 3.6.13-3.1 release available at:
Index of /repositories/mozilla/openSUSE_11.3/x86_64

(It's identification string: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv: Gecko/20101203 SUSE/3.6.13-0.2.1 Firefox/3.6.13)

I've spent a few hours trying to debug what I assumed was an application design error, but have since been shown that it is actually an issue with this application.

With all extensions disabled, I can reproduce this:

Set a cookie, require cookie for data on a page to display. Load page. View page - no cookie data. Ctrl-R (reload page in view source), cookie is found.

I've tested this in PHP and various CGIs, and have been able to reproduce this problem specifically across this build. Similar builds for other operating systems do not have this error - I posted this here to hopefully aid anyone else trying to debug this issue.