I think it will work for you phorem
phorem from your post, you have the "too many northbridges" error. that was fixed inbetween 2.6.0-test11 and 2.6.0 final.... there also was some amd64 sched stuff that you might need in the new version... so are you sure you have the latest?
oh and I was using 4499 version nvidia... I couldnt get 4620 to compile /* complains about the arch being 64 not 32 , I didnt pursue it more than that */.
I really didnt do anything special. I just seemed to work, to my suprise.