Connection Issues Ubuntu 11.04 (Guest)

[ubuntuonvbox]

I am running Ubuntu 11.04 on Virtualbox 4.0.4 (Winx XP host).

I am using my work laptop and installed Vbox on a portable HD using Portable Virtualbox.
Everything works great on my home ADSL and I can also connect via WiFi.

At work, however, I am battling with the following:
I can connec to the internet OK via the company proxy-server on Firefox only.
However, as soon as I start the Ubuntu terminal application the internet connection doesn't work.
Ditto for Unbuntu update manager.

I have also set up the proxy settings in the Network Settings preferences

Any advice will be greatly appreciated.

Thanks

[Perryg]

We do not support Portable VirtualBox