Sketch up keeps crashing when using push/pull and move tool

I have just downlaoded SketchUp free about 3 days ago, to check this software out. The program keeps crashing when i am using the pull/push tools. I get a mesage that the webpage needs to reload due to an error. I have used this program on two different internet providers, both with good connection and speed but the programs crashes on both providers. Please can anyone advice me have i can resolved this issue?

What browser do you use? Free works best with Chrome or Firefox