Source SDK - Hammer Editor - Missing Grid Lines

I just created a mod using the Source SDK and set it all up. Then I opened up the Source SDK and ran the Hammer Editor making sure the Source Engine 2007 and my mod was selected. When I opened Hammer and created a new map, there were no grid lines. I tried Map->Show Grid and pressing Shift+R. It didn’t work! Can someone please help me!?!

[editline]10th January 2013[/editline]

Also, if I try to load a map, it will begin to load and then Hammer will close down. I really need help!

[editline]10th January 2013[/editline]

Ok, I fixed the grids but Hammer still crashes everytime I try to place an entity or load a map. Can someone please help?