Wireless connection times out

I am sharing a wireless connection with my neighbour and while she
hasn't experienced any problems, my connection has been exhibiting a
perculiar behavior. While streaming or existing programs such as
internet radio or even GChat continue to work without a problem, after
a while of using the internet visiting new websites is no longer
possible forcing me to restart the connection. This happens at
irregular intervals and once it has started visiting any new site (or
even refreshing an existing one) displays the generic message 'The
Page Cannot Be Displayed"
Please help, thanks Elan