Not remotes related, and I've got 3GB of memory, mIRC is only using 27-30MB.
Pauses when joining a channel are expected, as yes, I do staggered delayed /who's to update IAL's etc..
And I agree that the updates of nicklist coloration should be done upon event trigger, such as a join or mode etc..
In any case, to loop through and check each individual $ial() entry in mIRC Script takes considerably less than the pause that's being witnessed..
