The X12xx series IGPs are the AMD RS690 chips. They are not true X1xxx series chips and are actually closer to the X700 chips.
I have gotten the game running on an X1200 on XP with no issues - the onboard graphics seem to make the whole system sluggish (right from boot up) though so they're not great. Try installing the original chipset drivers that came with the motherboard - though I've gotten the game running on the latest drivers as well.
To be honest though, I would have thought the button fix would have solved this. Are you absolutely sure you installed the files in the right place? I say this because several people have gotten this wrong in the past.
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