Problem solved: needed a timer
Code:
on me:*:JOIN:#: {
  if ($chan == #channel1) { .timer 1 30 run an alias }  
  if ($chan == #channel2) { .timer 1 30 run another alias } 
  if ($chan == #channel3) { mode # +isnt } 
}

I refuse to engage in a battle of wits with an unarmed person. wink