Blargh - my replacement Surface Pro is now exhibiting random issues with the USB port. It will sometimes just stop working for 1 - 3 seconds, then find the device(s) again and work normally for an indeterminate amount of time. Good thing I just moved near a MS store, I suppose. That and when I got the replacement, it rattled when moved. Should have been a sign I took more seriously!
I love this device, I just wish they were a bit more reliable.