help for portal 2!! Please!

[JSchizzle7070]

i recently got portal 2 by steam and when i shoot 2 portals i cant see through them. The portals just look as if they arent "connected" like as if I only shoot one portal... what do i do to make my portals see through? But i can go through them. Portal 1 works just fine! I tried putting in -windowed for the launch code/thing it didnt work. please help me!