ttb

tonight was driving, 4th gear, gave it gas, going about 70 mph and boost wouldn't build...stayed at 4 pounds and wouldn't go up. and i think the rpm wouldn't climb either (or was climbing really slow?). so i'm like wtf. decided to shift to 5th and boost went up to 11 pounds, as expected. downshifted back to 4th, and everything was working again, boost was ok. anybody experience this before. was something stuck? was the ecu crapping out? i have a power fc.

thanks