It may very well be something in the scripting engine. There was a decent amount of activity in two of the channels and no issues so far on 7.45 (main) or the 7.46 (testing).

Only script in testing one is a startup one that makes two connections to the twitch server (two different names and different set of channels). Also starts up a timer that updates the titlebar with the current mIRC uptime. Uptime thus far is almost 16 hours.

Have the same performs executing (enables additional info from the server), so everything is essentially the same except the lack of scripts.