Web Platform hardware errata
Q2 back-to-front (v1c only)
Check that Q2 (the 32.768 kHz crystal) is correctly oriented and not back-to-front. Seeedstudio have said that some of the first 20-30 boards might have gone out with a backwards crystal. Forum posts have confirmed that some were in fact shipped back-to-front, so it is definitely something to check if the real time clock is not updating.