help with 2 sketchup + vray problems

Hi, I have some problems with sketchup vray that I have only encountered recently.

1. Black squares instead or rendered image appears after passes. If i close the render window, BUGSPLAT! If i wait for it to finish, BUGSPLAT! If I press print screen, BUGSPLAT!

2. When I successfully render an image, to do another render (same file) I need to reopen sketchup. If I don't, the render will not start.

Please help me with these problems as I have some deadlines coming up (and some have passed already)