Now some months later, when shutting to door (/w the garage door opener). it stops (about 2/3s down), and goes back up (seems to think that there's an obstruction). To get the door to shut cleanly I have to assist (pull) in it's downward travel (apply additional load to the door, to counteract the springs).
My guess it that the "new" springs have been set incorrectly. If I try to shut to door sans garage door opener, it takes some effort to pull the door shut - particularly in the last 1/3 of it's travel.
Is my assumption correct - should I call in the original contractor to adjust the springs. By the way I have tried to adjust the garage door opener (set screws) but to no avail. Garage door opener is a Sears brand /w rubber drive belt.
Prior to the broken spring there was never a problem closing the garage door /w the opener.