All the slowness I experienced yesterday has disappeared somehow. I can't reproduce the slow window opening and switching and slow scrolling anymore.
I didn't change anything to my configuration: no changed mirc options, no software or hardware changes. All I did was shutdown my pc, go to sleep and restart it. I would be very surprised if a cold start would have been the solution for these problems.
I'm sure it wasn't my system as a whole that was slow yesterday, since everything else behaved as usual. Even when switching between v6.16 and v6.17 to test, it was only v6.17 that had the slowness.
Really puzzled now...
