I'm not very happy with the Negafix Profiles for Kodak Portra and Ektar. The colors and brightness are off quite a bit. After trying several things I stumbled over a weird situation. When I make a prescan with the correct Negafix profile selected (in this case Kodak Ektar) the colors are off (here too red) and the brightness is a bit too high. If I go to Edit->Preferences->CMS and switch the internal profile from ProPhoto to AdobeRGB, the colors of the prescan instantly change to a better, more correct version. If I switch the profile back to ProPhoto afterwards (while still being in the dialog) nothing changes with the prescan.
Here's a comparison. On the left is the bad looking scan with ProPhoto selected in the CMS options. On the right is the prescan after I changed the profile to AdobeRGB in the Options dialog.

Thanks,
Andreas Resch