As long as they are current issue live chips I have never had a problem cashing any casino's chip at a Harrahs property- mainly the Flamingo.

To cover their rear ends, they have a catalog book of all live chips in use in Southern Nevada, although I think they might have overlooked a couple of Riviera $5's from the 2005 convention and just paid me for them.

From what I've heard, many hotels offer chip cashing from other casinos as a customer service- check before wasting a whole day and a tank of gas.