I had similar problems when I started kegging. What I've been doing, and have found to be more successful is to only force carb for 24 hours at 30 psi. Bleed off all the CO2, then set the regulator to my serving pressure. Which for me is typically around 8-10 psi.
If the beer sits on high pressure for any longer than a day I have the same issues you have, and it ends up having to sit another day on low pressure before you can get a non-foamtastic pour.
The line comments are good, too. Can't remember what length my lines are, but when I stepped up from the odd length hoses, and had 6-7 feet on all my kegs, they were way more consistent. Really looking forward to getting a kegerator so I can have a nice, clean, organized space for the kegs.