One every 12 seconds is also not even close to enough to cause any noticeable delay with GDI, again, no matter how slow GDI was.. In 12 seconds your computer has processed trillions of instructions-- the one GDI message wouldn't even amount to a quarter of a percent of your utilization. Ping/Pong events should immediately be ruled out as a possibility.
205 channels is a lot however. I could see that as being the cause. For every channel, mIRC maintains timers and other auxiliary information that is frequently updated in addition to many more GDI messages than the ping/pong event every 12 seconds. This is even more significant if you join all the channels at the same time (in an ON CONNECT event or using a bnc, for instance) because all internal housekeeping will be triggered at the same time. That could account for 5 seconds of delay every N seconds in a systematic fashion.
I should add that everytime I've heard of this freezing issue, the user was either on 100+ channels on multiple networks or had a bnc that maintained many channels for them. It is actually pretty well reported that mIRC doesn't handle many channels all that well. I really wouldn't be surprised if this is the case.
Can you reproduce the freezing on say, 5-10 channels across 1-3 networks?
