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.
You don't by any chance have a smartcard in a card reader, do you? If so, try removing the smartcard. (I had a similar issue with a smartcard and Firefox; removing the card from the reader got rid of the dialogs)