If your computer is a MacBook Air and you are establishing a hard-wire connection using Apple USB Ethernet Adapter, your internet connection is cut off when you connect the card reader to the computer’s USB.
This is not an ID-software bug.
MacBook Air users reported this error to Apple in 2011. (https://discussions.apple.com/thread/2768456?start=0&tstart=0).
Regretfully, there is no solution to this problem yet.