Internet Connection Failure...

Weirdest thing happened. After starting my laptop (Dell XPS 17, Windows 7), I had no internet connectivity. The network connections were fine - I could see other machines on my domain, but no connect out to the internet. My laptop is set up with an external monitor (LG Electronics 34UM94-P 34-Inch LCD - waaay cool!), mouse and keyboard. And the keyboard and mouse are USB connected to the monitor, which in turn is connected to the XPS laptop.

Did a bunch of poking around for possibilities. In the end, what worked was shutting down the laptop, unplugging the USB and the monitor, and then restarting the laptop. It came up fine, with full network and internet access. Then plugged in the monitor - still had internet; and then the USB. Internet and network access was fine and the keyboard and mouse worked.

Don't know why, but recording this for posterity!