cig lighter half on/half off

HELP!!! ((1991 Honda Accord)) I recenty noticed a problem with my cigarette lighter. my friend bought me interior lights from HongKong that take power through the cigarette lighter. However, when i plugged it in, the lights didnt go on. I checked to make sure the lights worked by plugging them into my friends bmw m3. Sure enough, they turned on when the plugged was placed in. To determine if my cigarette lighter was completely broken or not, I plugged in my ericsson phone charger to double check. To my surprise, the charger started charging my phone. However, if i rotated the plug, it would stop charging. Consequently, if i kept rotating the plug, it would charge in some areas, where as in other areas it wouldn't work at all.

**Does anybody have ANY clue?? HELP!!!**