One thing that sometimes fixes problems is reinstalling the drivers. Go to the Belkin site and download the latest drivers for your adapter, don't worry if they are the same as the ones you are using, get them anyway. Now boot your PC into Safe Mode, go to the Device Manager and uninstall all the Wireless network adapters shown. Open the Add/Remove programs list and check that any references to the Belkin card have been removed, including the connection manager. If there are any there, remove them. Now boot back into Normal mode, your card will be found and Windows will search for drivers. Point it to the new drivers you downloaded and install them. You really only want to install the drivers, if you get an option to install the Connection Manager, cancel it.

It is possible that the router is just not sending out a strong enough signal for your card to pick up consistently. If this is the case, fitting a higher gain aerial to your card may be the answer. If you are inclined, you can test this by moving the router close to your PC and see if you can pick it up. You do not need to be connected to the internet to do this. You only want to make a connection to the router. If it connects easily, then signal strength is your problem.

Alternately, if your Belkin router gave you a good result before, you can connect it to the Sky router and take advantage of it's better wireless performance. You will find instructions on how to do this in THIS thread.