Spot on both of you. Below 5mph the ABS ECU is in diagnostic mode, you can interogate faults. Once it sees all 4 wheel sensors count up to 5mph it switches to running mode and can't be interogated. Shame because you can't see the condition under which faults occur.
Anyway, it's easy peasy to clear the fault in the ABS, yo uneed a peice of wire and some patience. There's already an article in the workshop (or I'd have written one) and the realy you need to ppull out is under the passenger's seat, the back one of three on the outside edge, it's blue and will click as you remove it if the ignition is on. The find the blue plug behind the pull down panel and short the black/black-purple wires and count the pullses on the warning light. When you pull the short wire back out it clears that fault, continue 'till no faults are displayed.