Strange spalek83, i also have 8500GT 256MB DDR3 but no lags, using dsdt gfx injection though. When do you have that mouse lag, when on desktop or when playing itunes or quicktime? Asking that cause we had that lag back in 10.5.x caused by new quicktime libraries (there is a fix for that) but in 10.6.x that's fixed and i never had any kind of lags.

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