pho3nixf1re

This may help you, took me awhile to find. The global user password is md5 hashed in the authenticate method of the plugin. This interferes with the way wordpress processes the password for authentication. Just remove it.

$username = phpCAS::getUser();
$password = md5(CASAuthentication::passwordRoot());

becomes

$username = phpCAS::getUser();
$password = CASAuthentication::passwordRoot();