Sims 2 expansion pack problems

I have installed the sims 2 and several expansion packs. The problems is that when I try to acess a previous expansion pack's features (the last one ive installed is free time) for example I may try to go downtown on sims 2 free time. When I try to click on the icon, it says "you must have sims 2 nightlife to acess this feature". I have sims 2 nightlife installed. what is the problem???(this happens with every other expansion pack also)