Yes.....I'm having the same problem on my 64 bit install. It was there but then disappeared.I'm not sure if it is specifically an x64 issue... any one else out there in the US having this issue?
I couldn't get Windows Media Center to work so I reinstalled using the XP upgrade instructions using custom. This installs Windows 7 as a clean install and wipes out all of Vista. Now I have internet TV and Netflix back in Windows Media Center. The only thing I had to do was go to devices and upgrade the drivers from the internet for my Happaguage 1600 TV tuner card. I can't play blue ray dvd's. The software for my LG blue ray DVD player still doesn't work....Power DVD Ultra. I guess it is now a waiting game until Cyberlink updates the software to work with Win 7 64bit.
I'm based in the UK running 32Bit Home Premium. I installed Internet TV on first use and it worked fine for a day or two. Then it stopped working! I can see all of the channel data strips but when I click on any of them (inlcuding Live TV) I get a confirmation 'beep' but stay on the same page.
I contacted Microsoft support in the UK and basically they advised it is a known problem for which there is currently no fix. They will advise me when a fix comes out - I'll wait and see!
Did you upgrade from Vista or do a XP install which is a clean install? I fixed my Vista upgrade installation by following the instructions for a XP install(on Vista).