I can't add any useful knowledge here; but my problem is very similar. A skilled friend installed the new 2tb h.d. I had bought from ifixit, after the original h.d. had suddenly died; but when I tried to load osx leopard, it didn't work so then I went back to tiger--in both cases the computer or startup disk did not see a destination disk at all! The new h.d. might as well not exist. Unrecognized. How can I make use of the new h.d? At present I am running tiger from my back ups external h.d. I hope that is a very temporary pro tem solution and that I will be able to load osx snow leopard onto the new 2tb h.d.