The ISO is automatically controlled when WDR is enabled. Also, if your scene is set to anything other than "none" (i.e. fireworks, sports, etc.) ISO and a few other settings become inactive. When you use your camera scenes and modes in be alternate function other than normal, or none, the camera optimizes internal settings to factory recommended settings. as with any digital camera, those scene settings can be slightly deceptive. for example: you're in your car, driving down the road. you want a picture of that hairy yack that keeps eye-balling you. setting the anti-shake to enabled may not be your cup of tea. instead, try the sports scene. since you're in motion, the sports scene user a faster shutter speed than normal. or, keep the scene to none, and use the spot metering, as it will apply focus to as much of the foreground and background ar necessary... just in case you miss aim. resorting all of your preliminary features to off, or none will generally allow you to customize other settings.
