You're not the only one with this problem - I've been in contact with HP support with this problem for over four days and diddly-squat has been done - I just keep getting 'escalated'. I'm starting to think there are compatibility issues with Vista and this blinking printer. Ring HP support on 0870 010 4320, ask for a Technician and request that they talk you through a system scrub. It removes all the HP printer software - didn't work for me, but it might work for you.
Have fun with them!!