I have a bit of the opposite problem, but sort of the same.
My Mac laptop (bought a year ago with game playing in mind) runs all the Sims EP just fine, but my husbands PC, with Vista, has the same problem of crashing the game after only 10 seconds. It will tolerate nothing more than the base game, even updating that game causes it to crash, every time. Before you ask, my husband just updated everything in his computer this summer (he's an avid gamer.)
Anyway, what I'm trying to say is the problem has been around before LN and I've got no suggestions. My husband and I have purged our brains of ideas (and did an extensive internet search) and nothing has worked. Hopefully things go much better for you lucidsounds. Good luck!