[Sarcoth]

Make sure you have Enable Forum Leaders set to Yes.

Admincp > vBulletin Options > General Settings

Or, you can probably remove the following code from the showroster.php.

if (!$vbulletin->options['forumleaders'])
{
	print_no_permission();
}

Another problem might be whether or not a usergroup can view the Forum Leader page. I'll have to check the Usergroup permission for that. Removing the following code may fix that problem as well.

if (!($permissions & $vbulletin->bf_ugp_forumpermissions['canview']))
{
	print_no_permission();
}

Let me know how it works out.