Ethernet shield and webpage

Hi!
I have been testing and stealing and changing code for different sketches trying to learn myself some coding.
I have now drifted into testing networking and I have hit a wall, hard.
I have an UNO, and a W5100 from HanRun (HR911105A)

Based on some tutorials and examples loaded from the library I have managed to make a very simple website for turning LED on an off.
And here is the problem:
The website is accessible from all PC/MAC/Chromebooks on my LAN.
But, none of my pads or phones are able to connect even thou they are on the same LAN
Other websites on the LAN is OK but not the Arduino website.
Any ideas?

For simple explanation I can refer to the code used in examples, Ethernet2, webserver.
Why will it not display on mobile/pad devices?

Thx

BTW, I can ping the ethernet shield