If you have aftermarket levers, make sure you have slack/play between the lever and piston rod.
I have had several customers come in with sticking front brakes... I myself have had that problem.
The problem is that the lever doesn't allow the piston to return past the bleed orfice in the mastercylinder and
the fluid has no place to go and pushes out the caliper pistons..
Good info, Noid. +1 on your karma, bro!