wrong units on mobile site

First of all - excellent site!! one issue though - I've sighned up to the coaching function which is great, but the information on the website using my laptop differs from that when I use my iphone.. I think the issue is with the mobile site, because it gives the 'next run' in km which is shoud, but the distance is equivilant to the milage. ie, my next run according to the website is 6.43 km (4mi) and the mobile site tells me my next run is 4km. please can you have this fixed.