Thats not exactly low boost, but I would suspect a leaky puck, which sould be leaking from not closing all the way, the puck shaft binding up, carbon buildup, misalignment...I would pull the downpipe and take a look. Maybe you dont have enough adjustment with the rod. You still didnt answer XLR8's question. What was boost before the changes? Your boost gauge could simply have problems. The hose going to the gauge could be cracked, have a hole or leaking at the barbs. Or the hose could be too soft and the hose is ballooning...some of the boost could be wasted on ballooning the hose...not likely though. I would check the wastegate puck, the gauge, and for hose leaks either through the hose or through the barbs at the ends. Where are you getting your boost reading from?
THEN MAYBE YOU COULD HIT THE CAPS LOCK BUTTON.