X100 Overexposure Not Related To Sticky Aperture Blades

I've had my x100 for about 8 months now (serial 14xxxxx).  Used this wonderful camera a lot and familiar with its performance.  Just recently I've noted mild but definite overexposure in most every pic I've taken--Typically have to set exposure compensation to about -2 to get proper exposure.  Pretty sure not SAB as I can see that blades do close down with increase in f stop.  I use auto ISO (3200 max with 1/40 min shutter) since I've had the camera.  Still overexposes with Manual ISO
too.    Typically use aperture priority, multi photometry, auto iso as noted  (firmware 1.21)  Less overexposure with spot metering but i have always used multi.  This is definitely new behavior--any one else have this problem?  Any easy solution?  (i have posted this same question in another X100 forum)