I installed the 2.6.29 kernel and in fact I can not install the nvidia driver by debian way or nvidia way :S
I understand what debian guys are trying to do. If there is a kbuild package, it should be used to build things. But what they are doing is breaking every thing that do not uses kbuild method. Sooner or later will be possible to install the nvidia driver by debian way but i really doubt if nvidia will spend time to change the way they build its kernel module.