Problem installing Sims2 Packs (lots)

I'm not sure this is Pets related but the problem seems to have arisen around the time I installed Pets. (I've got all the other EPs too). Anyway, I can now no longer install Sims2 Pack lots. I've researched this problem both here and MTS2 and found others have encountered it but none of the solutions offered seem to work for me. It's been suggested that I use MTS's Clean Pack Installer but that offered up an error message involving not being able to find a file called "localpackages.txt." The TS2 installer says I'm missing expansion pack files (it'd be nice if it said which ones). Compared to some of the other problems I've been reading about from Pets users, this is relatively minor, but solving it would allow me to do some things with my neighborhoods I've not been able to do recently. Let me know if you need more details. Anyone who can help I'd greatly appreciate it. You may PM me if you'd like.

Thanks-- Jay61