hi there gafi, to fix 'About This Mac', try the attached AppleSMBios.kext. Backup your old one before though. The latest AppleSMBios.kext by mac.nub doesn't work for me either.

Also, do you have QE/CI (Quartz Extreme & Core Image) enabled? If not, this could be the reason why some applications aren't working.

With QE/CI, every Application should work. At least it does here on my AMD Machine.