Comment 2 for bug 137758

mewt:
I've had a look but I can't find the bug (if there ever was one) where this was mentioned in detail (Martin PItt briefly mentions the issue in https://bugs.launchpad.net/ubuntu/+source/linux-restricted-modules-2.6.20/+bug/99122/comments/5 ). Basically because there is more than one linux-restricted package which can satisfy an install for nvidia-glx apt basically fell back to the wrong one. You would have already needed the correct linux-restricted-modules to have already been installed (which is generally the case unless you manually uninstall it) for it to guess correctly.

As a side note you may find that your system fails to keep the NVIDIA module up to date with kernel updates due to missing meta packages.