I have seen this as well, with a user running IE11 to access osTicket V1.9.11 on Ubintu 12.04.1.He reports that just getting out of IE doesn't fix it, but rebooting his computer does. Leaving IE open, Switching to a Firefox window, logging in and performing the same Advance Search works fine. However, he can't make the issue show up on demand--it only happens once in a while and he can't say what causes it.