Hi Chris,
Is this still an issue? I've not had any issues creating profiles for my G10. I usually just export to colorchecker from within Lightroom 3 but don't have any exposure issues when creating or using the profile.
Although the G10 is DIGIC 4, the smaller CCD coupled with the high 14.7Mp sensor offsets the capabilities of DIGIC 4 when compared to its performance on a larger CCD where the individual pixels are larger and heat dissipation from the CCD is better.
Regards,
Richard.
www.richarddavisphotography.com