It could be a problem with your network card. What kind of network card do you have and you said this was a laptop correct? If so, what brand and model?
I hate to say it but I always have problems with the Atheros network adapters. Try This:
Get an Ethernet to USB adapter and see if this will work for you. These cost about $15-30 and you can use this to see if you can get this to work or not. Is this computer still under warranty?
The IT guy recommended a USB ethernet drive as well, but doesnt the connection go via the adapter anyway? Its only 6 months, which is them most dissappointing thing about it.
