Windows 7: Media Center dies, wireless goes down

Maybe this is strictly a wireless problem. My config:
HP S3750F with Windows 7 Home Premium, using wireless 802.11n. I am not usnig Homegroup and have disabled IPV6 (as advised elsewhere); when I first disabled IPV6, it seemed to behave OK, but that only lasted a day. I use WPA2 security.

HP Windows Home Server on a wired connection, running Twonky Media (PVConnect in WHS).

I also troubles accessing music using Windows Media Player, but the network connection stays alive much longer and WMP doesn't crash when the connection is lost.

When I use Windows Media Center to connect to the PVConnect stream to access music, often MC will not show any album art. When this happens I will be unable to play music. I can select an album, see the songs and their length, but play button brings up first song and then the timeline stays at 0:00.

Sometimes MC does show album covers, albeit slowly (it seems to refresh the album art every time I connect to PVConnect). In this case I am able to play the music. However ...
It will often die after 5 to 30 minutes. When this happens I get a message that Media Center has shutdown, it will send a report to Microsoft and then it restarts. Once it restarts, it will no longer access music ...

but in this state, I see a yellow caution sign on my wireless icon. Windows 7 thinks that the connection to my local network is still OK, but it cannot reach the internet. Turns out it is lying - it cannot reach any other computers on my home network. All network diagnostics claim that everything is hunky dory. I have not looked at the report from ipconfig.

To repair network connection, I disconnect, then reconnect, only to experience the whole sorry cycle again.

Event viewer has given me no clues. OMG, there's a lot more in Event viewer than there is with Windows XP!

Any ideas for me? Thanks.