None of them, huh. I'm using a Samsung Galaxy Tab 8.9, wifi'd thru my smartphone, and this adds to the router overhead due to extra addressing. This often clobbers the 'payback links', which goes away when I wifi link thru ATT's server in town.
You can try to select/copy/paste those above links into a text file, restart your tablet, then try them from the text file. If they then work, you may be dealing with a website specific security setting in your tablet, or a server limitation, addressable by your provider.