Boosting problem Profec B II

[sr20tom]

i was runing in e-town this weekend with 100 octane after milking the car there, and wanted to bump up the boost to 18psi. I have a profec b boost controller. I raised the gain like crazy and all i got was a 17psi boost spike and then the boost ran at 12 psi all day. The book said if a boost spike occurs decrease the gain. The boost didnt fall of as quick but would only boost 14psi. So i added the % even more. The car went to 18psi and then the boost fell to 13psi. The book said if the boost falls off at high rpm add more gain. The gain is at the max 35% and if goes to 18psi and keeps falling after to 13psi. How do i fix this? If my BOV leaks or there is any kind of leak woudnt the car bog? I donno what the problem is????

12psi and 13.2 ET is still pretty good. at 18psi i should deffenatly be in the high to mid 12s.