i've got a mac pro xeon 2 x 3ghz quad core intel and 4 gig of ram (800mhz ddr fb-dimm). the computer is running snow leopard with the most up to date software. inside is an 8800 gt. to the touch the card gets pretty hot. the fan spins i blew the air out. after letting the computer rest and rebooting it works normal again but im afraid my client's machine is going to get that artifacting again. also when the artifacting occurs the computer moves all the icons around to the corners of the screen and the mouse and keyboard stop working. seems like a video card problem but before i order him a new card i want to know for sure that that will fix the problem. also will any pci express card work? i was thinking something along the lines of an ati hd 5770. would that be an alright replacement? thank you for the help.