<p>I just had this problem with my Nikon D100. No matter how I set the shutter speed it was very slow. I tried resetting my D100 several times but to no avail, the shutter speed remained very slow. I went into my menu settings and on #24 "anti-mirror-shock-mode" it was turned to the "on" position for whatever reason. I switched the setting to the "off" position and now my shutter speed works perfectly.</p>