OS X LION - Safari not working in work since upgrade to Lion

I have upgraded my computer to Lion and my Safari work fine at home but it seems as if Safari doesn't recognise I'm connected to the internet in work. The computer worked fine before the upgrade and the internet works fine in Mozilla when in work but Safari will not work.

It is causing an issue as any other applications such as Second Life which I need for work will not connect either as even though I have WIFI signal can connect through Mozilla the computer seems to think it is not connected to the internet.

Any advice would be greatly appreciated.

Does your office have a proxy server? Or are there proxy settings in your System Preferences you don't need. Safari and Chrome use the system proxy settings, but Firefox can either use system proxy settings or they can be entered manually for the browser itself. I've had issues like this where anything using the system proxy failed, but Firefox with its own proxy settings worked. Could that be what you're seeing?

Here's another vote for what EvenStranger said. Slightly off topic - what sort of job requires Second Life? Reminds me of an episode of the Office where Dwight's avatar could fly...