Why does sims 2 celebration stuff disappear in my game when i install Pets?

I installed the main game, Pets, family fun stuff, glamour stuff, and celebration struff, but when I play the game, the objects in celebration stuff were missing. I uninstalled Pets and tried the game, the Celeb stuff were there. But when I reinstalled Pets, it happened all over again. What am I doing wrong? Thanks guys.|||Huh. That's really wierd. Did you check the main website and install the patches. They fixed some game glitches with patches that are for dowload on the main site. I included the link below. Try installing the patch after you install the games. I hope you get it fixed. I know how frustrating that is.