I'm not sure what exactly is going on. "Serving pressure" should be the same as "carbonating pressure"- in other words, pick the correct pressure for your beer, normally 15 psi at 45 psi, and leave it there.
Don't shake, agitate, move the kegs, or turn the pressure up or down. That should solve the issues, assuming that you haven't messed around with the pressures.
If you burst carbed the beer with a higher pressure, then it's probably overcarbed and that will take some futzing around to fix. Turn off the gas, and purge the keg several times a day until it's not overcarbed. Then reset to 15 psi and wait for it to carb up. Make sure your lines are 10' long or so- longer is even better since your system should be set at 15 psi, so consider 15' lines..
Broken Leg Brewery
Giving beer a leg to stand on since 2006