If its the same on multiple devices and after re-adding the account, it sounds like it could be a Yahoo problem.
BUT, meanwhile, do this IN THIS ORDER:
- Go to your Options > Device and find your Service Books and delete ANY entries related to your Yahoo account. There should be two.
- Now, do a reboot... with the BlackBerry powered ON, remove the battery for a minute, replace and reboot.
- Now, go back to your BIS account login, and resend the service books. You should get notice of receiving them in your messages.
See how that works after the first hour.