To pick up on quacker's line (3rd Jan), not just happening to other Airbus' elsewhere either. Just looked at an article in Flight safety news where the NTSB is assisting the UKAAIB investigate an Easyjet 737-700 non-revenue lease handback test flight plunge of some 10,000ft and exceeding VMO over 100kt, link...
EasyJet Boeing 737 plunge being investigated by AAIB and NTSB