Belkin g+ mimo caching problem
 

I have a Belkin F5D9230-4 v5000 wireless router. I configure router and internet is work on both computers with no problem. Everything was fine until I realized that my youtube or any similar website don't works . Starts to load, and it stops around the 10% mark and seem to get stuck and won't go any further. I've set up the router exactly as they said and set up the security as they said too.
Thanks for eny help