When i connect to the internet (ADSL) i'm able to download about 10/15 websites before my computer just seems to stop being able to download and display websites. The connection isn't cut off as i'm still able to use Messenger programs and ping remote servers

I'm currently running Windows XP Pro with a Sygate Personal Firewall. Both are configured to work correctly as far as i know.

Does anyone have any idea of what maybe the problem ? I'd be really greatful. At the moment i have to restart my computer after downloading the 10 / 15 websites which really sucks.

Thanks in advance.