gravexgirl Does this happen in a new save too? Please test for comparison's sake.
If the new save is fine, test different sims in your main save, and the same sims but moved to a different lot. You don't need to save your progress.
If the new save is not fine, please provide a dxdiag. Click Windows key-R, enter dxdiag in the run box, wait for the scan to finish, click "Save all information," and save the file to your desktop. From there, you can attach it to a reply using the paper clip (Attachment) icon included with the other formatting buttons.