Blinking
Blinking is when a dog finds a bird, points quickly and then shies away from it, sort of pretending like they didn't see it. It usually happens when a dog is corrected around birds that are still on the ground (Jerking on the cord to hold him/her, yelling whatever command you're using to get the dog to stop etc). Best way to overcome this is to let the dog have all the birds he/she wants but can't catch and not say anything while they're chasing them. That will get the confidence level back up. If busting and chasing start to be an issue once the confidence level is back up, it can be dealt with. If the dog is soft minded, you'll need to be very easy on any other training, in the field or yard...and remember to give TONS OF PRAISE!