Can you try something for me? I think you may have found a bug.

IN templates/default/markallread.tpl
FIND THIS:
<form action="{ubb url="ubb=domarkallread"}">

REPLACE WITH:
<form method="post" action="{ubb url="ubb=domarkallread"}">


Test the button again (after doing a browser page refresh on the page), and see if that works for you now.

Thanks!


Current developer of UBB.threads PHP Forum Software
Current Release: UBBT 7.7.5 // Preview: UBBT 8.0.0
isaac @ id242.com // my forum @ CelicaHobby.com