Fix for SD graphics write API failure

Unzip the SDK ...

	AltitudeSDK_1.2.0.60b_2005-03-15_SteveP.zip

... to a clean folder and replace ...

	Driver\HpxDrv.sys

with the version provided in this update.

If you already have the Altitude drivers installed, replace HpxDrv.sys
in your Windows System32\drivers folder and reboot.