I have had zero problems. I am using Windows 7 with the latest up-dates, Firefox 15.0.1 and BitDefender 2012. As far as I can tell (I can't find it listed as a file anywhere), I do not have Java loaded on this machine.
However, I recently loaded Java 7 on a Windows XP machine. While I have not attempted to access TUG on that machine, I have received a variety of
"you are trying to go someplace unsafe" messages from the McAfee antivirus (as provided by Road Runner) on that machine.
I am in the group that thinks the Java 7 up-date is a primary candidate as the source of the TUG access issues.
Art