I have a well cared for OM-2SP that has problems metering at low light. In bright light it seems to meter fine, giving me excellent pictures during the day. In low light is where the problems begin. The meter registers as light coming in when there is no light coming in. If I put on the lens cap, when there is theoretically no light coming into the camera, it still registers at the same light level as a badly lit floor or a moonlight wall. If I change aperture and shutter speed, the meter registers a different amount of light, but it is still consistent for multiple different low light conditions. I've been using this camera reliably for the past year and only now has begun to give me problems. Any ideas or suggestions about how to fix this problem?