I'm having this really strange experience with all of the swimming pools in the game. I can't find anything related to it in the FAQ's, but it's only happened since my last game update.
Basically, my swimming pools appear to be underground. The surface is pretty dark & my sims just disappear when they get in, but I can click the 'go down a floor' button 1 more time & it takes me in to the pool, where my sims are swimming through thin air. You can see the walls of the pool but outside of that there's just a massive expanse of black. It creeps me out!
I've got a really good computer that's well suited for gaming, and The Sims 3 runs so smoothly. This is the only real problem I've had.
I appreciate you taking a look at this & I'll be grateful for any suggestions =]