Media Player 12

I got a laptop with Windows 7 ultimate - upgraded from Windows XP. I use the laptop exclusively to stream video from: Punto Final | Videos | Noticias | Television Peruana | TV Online
It used to play flawlesly under Windows XP but since I installed Windows 7 (with WMP 12), the WMP window shows for a couple of seconds "Opening media" and then shows "Ready" and nothing plays. Press the play button but no response. Tested at: PluginDoc: Windows Media Player Plugin Test Player (XP/Vista) and same behaviour. Under both Firefox and IE - same thing, yet my XP desktop plays the media fine from the website. What am I missing?. I am sure is something simple but have spent a week on this and still the same problem. Any assistance appreciated.

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