Xenon switching problem after upgrade

[staffop]

I've noticed since switching to Xenons from Halogens on my pre facelift X5 that both Xenons don't always come on when the Headlight switch is set to 'Automatic' (i.e. turn on automatically when dark). It always seems to be the nearside light that doesn't light up; yet if I turn the lights on manually they always both come on.
Is this a programming issue? Its quite annoying as you can't always tell both lights aren't on especially in the city !