well recently I installed sims 2 bon voyage and then after I started the game the weirdest thing happened.

the houses, the ocean, the cars and my sims everything, got divided into stripey and unclear lines, but when I moved, zoomed it momentarily went normal and the moment I stopped it again went strange. I have Inteeminater, but it worked fine before with my other expansion packs...
I have an NVIDIA geforce 7300... any idea what could be happening? I mean I can still play but it's agony

Tried updating your nvidia drivers? That's usually the problem..
If that doesnt work, how many expansions you have? It might be how the graphics card hasnt enough memory for your system.. also, is the ram low and your graphics integrated?
Hopefully I helped

I agree with maddie.
Download the lastest drive or change another video to have a try.