http://bugs.webwork.maa.org/show_bug.cgi?id=2078
and it's also related to this thread.
http://webwork.maa.org/moodle/mod/forum/discuss.php?d=1999
which the cookie patch was meant to fix. We'll try to get a fix ready
and then distributed in trunk. If someone has robust fix for the cookie problem already send it to Jason Aubrey or me.