My thanks go to Ciaran and the article about "Mobile Web Acceleration". I thought I'd never get a "fast" internet connection via my O2 connection. It seems that every page was trying to poll 188.8.131.52 and my ubuntu 9.04 laptop running firefox didn't like the result.
The answer Ciaran found is elegantly simple. Just do the following:
Select System>Preferences>Network Connections
Choose the "Mobile Broadband" tab
Select your o2 connection and click the Edit button
Now change the "Username" field to "bypass" and click "Apply"
Then you are done.
At last! - Mobile web renders web pages as though it were a WiFi!