Internet connection stops

I have a Dell Latitude E6540 connected to a Dell docking station, hardwired to our network using the Intel(R) Ethernet Connection 1217-LM. This has been working fine for well over a year. However, a bit over 2 weeks ago I updated all my drivers from the Dell Support site: BIOS, chipset, video, network, everything.

Then this problem started: Everything works fine all day long. But when I come in each morning, I have no connectivity to the internet. The network icon in the task bar still shows normal that all is connected, when I right click it and Open Network and Sharing Center, everything looks normal, but I have zero connectivity.

In Outlook if I click Send/Receive, I get errors that no tasks can be completed and that I am not connected. If I try to browse in IE or FireFox, I get errors that I am not connected to the internet. If I disable the wired connection and enable wireless, I still cannot connect.

The only solution is to restart my computer then all is well until I leave it overnight.

This morning I came in and surprisingly had connectivity. However, just a few minutes ago I lost connectivity. Icons all showed being connected but I could not access the internet, send/receive email, print to network printer, see network drives, nothing.

Running diagnostics showed that "There might be a problem with the network device driver."

I have checked all power savings, card properties, etc. to ensure that nothing allows the network card to sleep, etc.

HELP!