Billings has notified me 4 times this afternoon about the 2.5.6 update.
Generally I choose 'Remind Me Later' when I'm in the middle of using an app and don't want to have to stop to update (and possibly reboot my machine). Therefore, I would expect to be reminded of the update the next time the app starts up, not every 30 minutes for the rest of the day.
Hopefully this is a bug and not a design decision. Is anyone else having this problem?