Wirelessly posted (HTC Diamond: Mozilla/4.0 (compatible; MSIE 6.0; Windows CE; IEMobile 7.11) Sprint MP6950SP)
After you uninstall the bing app, wait a few seconds and turn your device off completely. Wait a min or two and then turn it back on let it finish booting. Wait a min. Then re-download the bing app from bing.com not the marketplace. Then reinstall. A few people have had isses with the marketplace version. Hope that works!