Thx for all the input, guys. Seems like I have been using the lens in wrong ways.
So here what I have been doing:
1. Always use live view for framing and focusing. So far no problem with that.
2. Have tried shooting with P, M, A and S, set the ISO to AUTO, live view will display correctly, but can't control the ISO.
3. Anyway, just realised that I have doing much complaining and not enough shooting. Will use the lens in the weekend, and will share more pictures, instead of more "downing". 
4. Thank guys!
cheers,
Sorry, man, but I can't really follow you. As far as I know there is no such thing as an "Auto-Exposure" chip. Light still comes through the lens and hits the sensor, and the camera decides the shutter speed the same as with any other lens. When you shoot, don't set it on "M"! Put it on "A" and the camera will set the shutter speed--it is only aperture and focus you have to worry about, and even these not much. If you are outdoors, crank the aperture to 5.6 for a really nice deep depth of field where most stuff will be in focus. I always set my ring to about 1.2 meters and everything is in focus from about 3 feet to infinite. When I got this camera I was worried about manual focus and such, but it turned out to the easiest lens of all to use. Never a missed focus
I don't even have to look through the viewfinder when I shoot, so it is good for stealthy street work.









