Custom content issue

I've been having all sorts of issues since I installed the Sims 3 Pets. Everything from lag, random freezing and crashes and even blue screens of death. It became so bad that at one point some of my computer registry files were corrupted, including some of the sims games reg files as well. After that I couldn't even uninstall the games in order to install everything again. I had to download the Your Uninstaller tool from the site to be able to remove the games.
I just finished reinstalling everything back again and applied the fix for pets and I've been installing my custom content back to the game. I've succeeded in installing most things, but some items fail to install, giving the following error messages:

"Error: requires expansion package."

or the most common

"Installation failed: make sure your game has the last Software Updates and try again."

Considering I followed the "How to install The Sims 3 correctly" tutorial to install all expansions and mini packs (all downloaded from the site, including the fixed version of Pets, 'cause I feared my old downloads could be the problem) and then applied the fix and my game is updated, I have no idea what the problem might be. Maybe this contents are just not Pets Compatible?

ps: I used TG Unblock 2 (from thesimstg) and the RigFix (from The Sims Resource) on the files before I installed them.