[otrs] search issue

Hi, We use otrs 3.1.6. if i have a ticket with subject "john & mark" and search for it using "subject" or "text" or "full text" search fields i do not find it using it's full subject line. if i only search on "john" i find it. I assume therefore it's the "&" symbol and likely other special characters that the search doesn't like. i tried to escape the character with \ but that did not work. is this a known issue, i dont find a bug report for it. thanks Neil