The redirect_to_url function may set \ instead of / in the url. In this case, Firefox can't redirect to the page.
In sb_login.php change :
function redirect_to_url( $relative_url = "index.php" ) {
$baseurl = baseurl();
header('Location: ' . $baseurl . $relative_url);
exit;
}
with
function redirect_to_url( $relative_url = "index.php" ) {
$baseurl = baseurl();
/* fix \ problem */
$redirectUrl = str_replace('\\', '/', $baseurl . $relative_url); /* ensure there is no \ in the url */
header('Location: ' . $redirectUrl);
exit;
}
Hope this helps
This is only a problem if a Windows webserver is used. Fixed in svn r70.