No background images.
(All set to none.
I have actually unloaded the scripts and then restarted mirc.
I will try again with an empty profile though as soon as I finish my current tests.
It seems that disabling multi-byte display seems to have helped a bit, but I will need a few days of usage before I can actually confirm that.(the issue might still be occurring only when buffers get full enough)
EDIT: here's the full trace by the way(the trace I always get during freezes though for all I know that function could just be called a lot or simply be frozen, since procexp isnt that clear): http://pastebin.com/m18403734
(not that it can help much)
EDIT 2: on a side note, a friend told me that he has the exact same symptoms. He uses a vanilla mirc and does not have much channels open.(he uses vista 32)
(and as me he sees it even when there is just one window open)
His experience is very similar to mine, and just as me he thought at first it was a dde issue and disabled it, which didn't change a thing.
The whole issue does seem interproc related though(or windows bugging), as there's no visible disk i/o / registry calls / network activity, and it occurs in the middle of mostly nothing.
The only common point we have is that we have japanese ime's. I will try seeing if disabling that can help.(I've noticed that the freezes very commonly occur when I type, but I always attributed that to the fact I wouldnt notice short freezes otherwise)