This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Sometimes it happens - the key is not updated properly during install/remove/reinstall. Just remove all java runtimes from your machine (including the manual removal of the keys from the registry, if neccessary), and install Java fresh.
Or, if you feel adventurous, edit the key directly in the registry.