Barryz:
I noticed that the LCD light is kinda dim, it not as bright when i connect it to the Arduino Board without the Ethernet Shield.
While I still think the real problem is pin clash, the above may not be directly related. Since the LCD works OK without the Ethernet being stacked, there is clearly nothing intrinsically wrong with it. If you are getting power from the USB cable, the above could be caused by insufficient power. The W5100 Ethernet shield is a bit of a power hog and it can be surprising how marginal the power is via USB. So, if you aren't already running off a wall wart, now is the time to do so.