This applies to registering at BG:
If you make an account here at BG at the start of a Sprint it could take hours for your CPID to validate. This does not happen instantly. It's recommended to register on BG a few days before the Sprint starts to ensure you can participate for the whole duration.
This applies to registering at the PROJECT selected for the Sprint and you already have an active and validated BG account:
BG uses your CPID to determine your stats. While the hourly stats do not rely on the stats.xml export file at project but rather the WebRPC feature to allow for hourly stats update it still has to verify who you are using the stats.xml file. This means even if you are registered on BG, with a valid CPID but you do NOT have an account on the Sprint project BG has no idea that you are there (since you're not). The project will need to export your stats to the stats.xml file as this file will have information for BG to use the WebRPC. That is matching your CPID with your User ID on the project. This can take many hours as so many things have to happen. Project has to update it's stats.xml, BG has to pull the new stats.xml file and export your CPID and User ID at the project, then and only then will your points start to count.
The sprint projects are listed at all times. It's highly recommended that you register at all of those projects BEFORE a Sprint starts, otherwise you may miss hours or even a day worth of points while the system is gathering the information to identify your account.
