Take the Belkin back to the store and get another brand. If you look through help forums all over the net you'll find complaints that their products have problems staying connected on a consistent basis.
Personally I've given up on all their stuff.
I had a Belkin notebook wireless card, well I still have it somewhere, and it just wouldn't stay connected. I got another card, a really cheap brand, and it never dropped connection, ever.
The only thing that changed was the card. Before I changed out the card I looked for fixes and found out about their problems.