1999 Dodge Dakota Brake question

Recently have had dashboard idiot lights come on indicating "Brakes" and "ABS". I changed the worn front pads two months ago. I checked my brake fluid levels (normal). I pulled the rear brake drums off this evening, to replace the rear pads, but they only look worn to 50% of the new pads. It appears that they have lots of life left in them.

When stopped, I have applied the emrgency brake, then released it when I drive away. The dashboard lights go off for about 1/2 mile, then they come back on.

The truck runs fine, and stops fine, but the "ABS" light and the "BRAKE" lights bother me.

I live in the North Georgia Mountains, and when I drive downhill and stop, the lights usually remain out. When I travel uphill, or across flat ground, the lights come on.

Any suggestions?