So my excitement for getting back into mapping was immediately killed when I went into Hammer 3.5 and found that 3D window was broken. It still displays fine, but I can't select anything in the 3D window. In fact, clicking in the 3D window will de-select anything I've selected in the 2D windows. Not only that, but it will not let me select faces or apply textures.
I've tried downloading a new copy (just the .exe), but that didn't do anything. So is it a configuration file or something? The Source SDK version works just fine.