Lubricate the posts the brake system mounts onto the fork, also lube the spring. Happened to one of my bikes, I used regular grease. then put back on. i also tightened it too much causing it not to snap back, so back it off a bit.
The bike is nothing more then circles turning circles, It's the human motor that makes it elegant.
I just had this happen to a neighbor on his brakes. Make sure the pads are hitting the rim and when you release make sure they are not so close to rubber that they are getting hung up. My neighbor crashed and moved the pads which caused his issue. We just loosened the pads, moved to proper place and retightened. Problem fixed.
I am going to second DriveBy. I am still running V-Brakes on one of my bikes and 99% of the time when the levers don't return it is due to the cable/housing. There is either crud in the housing which happens a lot when it gets wet or there is a kink in the cable and or housing which also just happens a lot. Check your cable and housing! Good Luck.