This is definitely a problem that Dell should address. I hadn't used my brand new Vostro 1720 laptop running Windows XP Pro a full day when I had the same problem. First I noticed that the network connection icon in the notification area fickered on and off a couple of times but stayed connected. A couple of hours later I lost connectivity completely. I tried disabling and re enabling the Local Area Connector but this didn't work. Only after shutting down the computer and then turning back on the computer with the wireless antenna turned off did I get the local area connector to stay on. I have been using it now a full day with the wireless turned off and I haven't had any further problems with the network plug.
I am having the same problem.
I tried the update by my computer uses a different NIC card (Realtek PCIe GBE Family Controller) and it didn't work. Also, when I try to update it from within windows it says that the card already is using the best driver. I uninstalled it and let windows do the auto update to reinstall it and my wired internet is still not working. My wireless internet does work, however.
Not sure if maybe getting a new NIC card would help? Suggestions?