Time Capsule is fine and has gone green. The first thing I'd done when it was blinking amber was go into system preferences and network, where it showed that it was green and working despite the blinking yellow light on the unit itself. This morning I called Apple and he took me one step further, to the Airport Utility screen, where the unit was amber. The reason? Firmware update. Firmware updates for the unit don't show up when the rest of the updates do, so unless you go into the Airport Utility you'd never know. So, we did the update, and all is well and well is all.