press 5 and also when u eventually begin texturing ure models to show the textures from photoshop as an example ud hit 6, to show the texture.(u have to hit 5 or 6 in each view to get them to show)
As for the slow down hmmm thats a weird one as the memory of 1024 is good enough to run maya fine.
Try getting the latest drivers off the net for ure card and the latest Directx from Windows site. not sure how these might help but they could.