Code:
on !1:join:#channel1,#chan2:{
  if (($hget(welcomed. $+ $chan) == $null) && ($isfile($scriptdirjoinsg.hsh))) {
    hload -bi welcomed. $+ $chan $qt($scriptdirjoinmsg.hsh) $chan
  }
  var %x = $hget(welcomed. $+ $chan,0).item
  while (%x) {
    if ($hget(welcomed. $+ $chan,%x).item iswm $fulladdress) {
      return
    }
    dec %x
  }
  hadd -mu1800 welcomed. $+ $chan $gettok($address($nick,0),1,64) $+ @*
  hsave -bi welcomed. $+ $chan $qt($scriptdirjoinmsg.hsh) $chan
  .notice $nick Welcome to $+($chan,!)
}

This is working for me, and you can do:
/hadd welcomed.#channel nickname!*@*/*!ident@*
then /hop to have it never send a message to anyone matching that mask. If you removed the u1800, then you should remove joinmsg.hsh, and type [/b]/hfree -w welcomed.*[/b], to clear all the lists, incase something was added. Alternatively, you can put your bot in a new channel, and join there to see if it works or not.

Those who can, cannot. Those who cannot, can.