Its normal depending on how much throttle you have and what rpm you are at. If the rpms climb but throttle stays the same depending on how the map is tuned boost will drop. Its been doing this all along and you probably just noticed it today. You seem to have a new problem almost every week.... My advice to anyone is to download Romraider (its free) and their stock map and have a look. It will help you understand how things work and how the ECU and the system as a whole is engineered. No cable is required.