type /debug @whatever
then use the script if it returns a raw EVENT halt it.
Well i found out for you that maybe its 401 returning the error
if you want to prevent this from showing type in remotes
raw 401:*:halt
and for the double channel thing I might suggest to use a if statement that if ($newnick ison $active) { do stuff }
$active being the current active window sure if the nick changes on a non active channel then it wont work which generally is a bad idea but oh well... you have the raw event.