Glad it's not just me
I've got the same problem with Windows 7 (64bit) & SH3 GW3.0+screen res fix.
i.e difficulty initialising 3D graphics unless I reset my desktop res to 1600x1200 or lower (Dell 24" 1920x1200).
Radeon 4870 with latest drivers, P5Q-DeluxeMB and Quad 6600.