Thanks to Digital Oracle for spotting this @ Athlonxp.com.

AMD Factory Gaffe has mislabeled processors. Processors that were labeled to be 333 FSB are actually 266 FSB. This is a problem with current stock. If you received your processor before about December 23, you likely have the correct processor. Just in case, there are photos of the incorrect (i.e. 266 FSB) processors on the left, and the correct (i.e. 333 FSB) processors on the right.