Error 104 on 3 dongle

I am using a 3 broadband dongle on my laptop - i have made no changes at all but the internet keeps crashing with the error message 104 or just 'web page unavailable'. I dont have a firewall running that would affect the dongle - has anyone any ideas at all, i can get onto the internet, think everything is fine, click away from the page or onto another tab and thats it... connection gone!

We get a lot of problems with these 3 dongles. Have you tried it in different locations, it could be a poor signal where you are. Alternatively, try it on another machine, that should identify whether the problem is with the PC or the dongle.