For some reason mirc uses an insane amount of cpu (close to 100%) when I scroll in channels or when I select some text. I've tried using a clean mirc install without scripts/addons/etc but it's still the same. I've also tried enabling/disabling Windows' smoothing of screen fonts with no effect.

Seems odd that a simple display of scrolling text should bring a rather new computer to its knees?

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Sysinfo: Core 2 Duo E8500, ASUS P5Q PRO, 512 MB RADEON HD 4850 ASUS GDDR3, 4gb ram, 1920x1200 resolution. Windows XP 64bit. mIRC 6.35.