well, as a GUESS:

Code:
menu nicklist {
[color:green]$iif($me isop #,Nick Tracker)[/color] 
    .Track Users
[color:blue] ..View Other Nicknames[/color] [color:red]{[/color]
    if (!$address($$1,3)) { echo $colour(info) -ti2 # * IAL not updated for $$1 $+ , performing userhost lookup | userhost $$1 | return }
    if ($hget(trackusers,$address($$1,3))) {
      var %n = $ifmatch
      if ($istok(%n,$$1,32)) { var %d = $deltok(%n,$findtok(%n,$$1,1,32),32) }
      else { var %d = %n }
      if (!%d) { goto notknown }
      echo $colour(info) -ti2 # * $$1 has also used the nickname $+ $iif($numtok(%d,32) > 1,s:,:) %d
    }
    else {
      :notknown
      echo $colour(info) -ti2 # * $$1 has not been known by any other nickname
    }
  }
  .Reset:hdel trackusers $address($$1,3)
}


Green is your newly added text with a slight change (and I DOUBT that would make it work but sometimes it can be weird). The BLUE is my question. It seems like there should be brackets of some kind (colored red) there (to me). Also, from the looks of it there COULD be a bracket mismatch going on cause I only see:

3 { (including the new one I put there) and 4 }

Those who fail history are doomed to repeat it