The problem would appear to be on nVidia's side and not the maintainer of agpgart. I received an email response from the agpgart maintainer saying that his emails to nVidia have been ignored.
Originally posted by erwos
The problem is not technically nVidia's - the maintainer of AGPGART needs to throw together support for the nForce2. Now, if nVidia has been witholding documentation, that's problematic. I've not heard either way. You'd think it would be relatively simple to submit a patch, though.