You are not alone, I do have the same problem with my 9ZHP but I do not have any problem with my 8UHP working with G2.

Please let me know when you found the answer!

I have the G2 installed in the Windows 98 system working fine, but when change my OS to XP I could not install the add on volume 3, I have tried all way, the G2 webpage guideline but no luck!