Hi all

Thanks Alan's advice, here is a patch that aims at fixing the mem. 
corruption problems encountered by some users, when trying to use 
agpgart with intel 815 chipsets.
The patch is against 2.4.19-pre8-ac5

Alessandro, could you please test whether this patch improves things or 
not ?

Best regards
-- 
Nicolas Aspert      Signal Processing Institute (ITS)
Swiss Federal Institute of Technology (EPFL)