If you are not properly logged in when you add a comment to a bug, and then it asks you to log in in order to finish adding the comment, it sends you E-mail about the comment even if you should have been excluded according to your preferences. Apparently, the determination of whom to exclude and/or to whom to send the E-mail is done before you log in.
This also happens if you try to run a named query saved under your username, using a bookmark, when you're not logged in. It prompts you to log in, but after you do, it says that the query doesn't exist. If you visit the bookmark again, it works.
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.
Please reopen if this is still a problem with the current version of Bugzilla (3.2).