Invisible pets/game crashes when try to create pets in CAS

I have had Pets since it came out but I dont really dont really give my sims pets that often unless they have a "want" for it. So as I played my game I realized that I never see any stray pets, so I went to add the pets family that comes with that EP that is in the family bin (I think they are called Critter or something) and there is no picture there, so I added them to an existing house/family they are there but they are invisible (if I click on their icon the plumbbob shows up but there is no pet there). also when I try to create a pet in CAS it crashes the game since then my game crashes after playing for just a few minutes. I have no idea what happened, I have taken out all CC and this still happens, I uninstall the game reinstall everything back up to Pets EP (all patches installed as well) and its still happening, I am at a loss now I cannot play my game anymore if I dont fix this becuase it keeps crashing if I play for even a few moments at a time if the Pets EP is installed. I uninstall the pets EP and it seems to have no issues with the game for the hour that I played, but I want the pets EP installed.

Please help me!

PC Info
I have all EP's and Stuff Pack
I have a Dell PC Inspiron 531
Window Vista
NVIDIA GeForce 8600GT graphic card (just installed the latest drivers)
3582 MB RAM
AMD Athalon Dual processor