Seems like every time I'm receiving NOAA-15 lately, about halfway through the pass the visible sensor will change gain (or something), going from a normal image to either almost all black or almost all white. The infrared image is unaffected, and NOAA-18 and NOAA-19 don't behave like this. I assumed that something was broken on the satellite, but the POES status page doesn't say anything about it. What's going on?