your post subject states DIR-625 but in the text you mention DIR-825. which one are you talking about?
Either way, I have not been able to get a connection speed above 58.5 on the router page... and streaming video is completely out of the question.
So far I have not had any success with this DWA-160 adaptor. My old 802.11b card outperformed my dwa-160 in every which way. Return it ASAP and get something else.