G&K: Mods appearing but not working

[Gress]

I have followed all the usual steps for making sure the Mods menu is visible and have put (and unpacked) CivUp into the folder ~/Documents/Aspyr/Sid.../MODS. The Mods menu appears as it should and I can enable the mod. However, it's clear from the game that the mod isn't changing the game at all. I've tried with a Perfectworld too but have had the same problem. Am I missing something really obvious? Have tried Thal's threads can't find anything about Mac issues.