Double check that you're logging into Impulse with the correct info, and if you are, try closing Impulse and running the following file:
http://sd.stardock.com/curthendzell/fix_registrations.reg
Make sure to follow the link in Internet Explorer, as other web browsers will not handle the file type correctly. Once you follow the link, save the file and double click it to apply it. Then relaunch Impulse. You will need to re-login with your username/e-mail (either will work) and password.
