In order to improve my connection speeds, I've connect my 360 to an ethernet internet connection. When I run the tests, I end up with the error message below. So I get a successful connection from Xbox -> Network -> Internet . But it fails at the final hurdle Internet -> Xbox Live. I went through the troubleshooting wizard (rebooting router, resetting xbox network settings) which eventually said check that the live service was up. Easy to check, I flipped back to my wifi connection ran the same test and all worked fine. I can't see how it could be a problem with my router as both methods connect to the internet and surely it's not concerned with the household side of things once it's gone out of the house. Likewise with the ISP.
Any advice is much appreciated.