Nuking gossip is an option on the Lot Debugger. It's either under the Memory menu or the Nuke menu. Clearing gossip deletes all the gossip memories in the 'hood, including any that might be corrupted, and it's not a bad idea to nuke the gossip periodically just to cut down on the amount of neighborhood information your game has to keep track of. The Sims will generate new gossip fairly quickly. Le gasp! Someone burned pork chops! Le shock! Someone kissed her husband!