Clock will not stay set on 2006 Bentley Continental Flying Spur

I just bought a 2006 Bentley Continental Flying Spur, and I can set the date and clock, but the system does not hold the setting in memory. Every time I start the vehicle, the analog clock resets back to 12:00 and the date reverts back to 2004.
I haven't fully read the manual yet, so there may be a solution. Any ideas?