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.

i had the same issue, was telling me my registration was invalid at the bottom in the status bar, but only showed error when i tried to install it.  i ran the reg fix, then it was gone from my account, i had to goto the store and re-add it

also, if this is the case, how do i know if any other registrations have disappeared, for any stardock stuff i've bought

bump

If you think registrations are disappearing from Impulse, you can get a full list of what should be present in Impulse by going here and entering your email address.

well, no, there was stuff missing, and i got that fixed, only problem is, i've been getting stuff for so many years, and have bought so much, how can i be sure that i have it all back in my account?

I cannot update the Quest package either, even after I applied the registration fix. The reasons for renewing OD are becoming fewer and fewer. I've not seen any NEW applications for quite some time.