Do you have a Belkin 7230 802.11g wireless/cable router version 7?
It'll look like the router in the adjacent picture.
If you do, we have been made aware of performance issues with these routers that may be causing loss of broadband connection and other problems such as poor performance on your wireless network.
Belkin have provided a fix to solve these problems, which involves updating the software on your router.
The update and instructions can be found on their site.
Please note that these routers are unsupported by Virgin Media, and we'd recommend contacting Belkin if you need any further assistance.