Bob,
I have a P200 that also had keys that stuck. Your particular unit may qualify for a keybed replacement through Yamaha. Certain units used a bad lubricant and caused keys to stick. As a result Yamaha will replace the keybed plus labor for free. You would have to provide them the serial number for your unit and if that serial number qualifies they will arrange with you to bring it to an authorized repair facility. You can reach them at (714)522-9011 and ask for technical assistance then provide them the serial number. Good Luck!
Tim, November 2009