Not being logged in, I added a comment to a bug and checked the "Add me to CC list" box. Bugzilla asked me to log in and then proceeded with adding the comment to the bug. However, it forgot to add me to the CC list. Not sure whether it is reproducible (have not tried it again yet), but it seems likely that the Red Hat - specific "CC list" checkbox was not fully added to the "remember what you were going to do when asking for login/password" code.
Just happened to me. Firefox 0.9rc on win2000pro. I added a comment to bug 120303 but forgot to check the "Add me to CC" option. So before the next page was loaded , I checked the "Add me to CC" option and clicked "Commit" again. Then the login page appeared. Just in case I clicked the BACK button and doubl-checked that "Add me to CC" was selected. Then I clicked "Commit" again, was asked to login, I entered my data and the changes to the bug were recorded, except that I wa not added to CC list.
Red Hat's current Bugzilla version is 2.18. I am moving all older open bugs to this version. Any bugs against the older versions will need to be verified that they are still bugs. This will help me also to sort them better.
Just tried to test it and it WFM.