Which 35/2.0 lens do you have? I assume an AF one. One that is manual focus only will probably be easiest to manually focus (AI-S or AI, for example). I have found this to be the case with my 10D. An adapted Nikon F lens always focuses easier than an EF lens focused manually.

Also, the screens on AF cameras only show you the D of F and brightness of f/2.8 or so. In addition to making it more difficult to focus, this also means that when shooting at apertures wider than f/2.8, you actually get less D of F than you see in the viewfinder. You also lose the center focusing aid on most modern stock screens.

Canon has type S screens to partially cure these problems, and I am sure Nikon has something similar. It is probably advertised as being "optimized for fast fixed-focal-length lenses", or something like that.