Good device with poor documentation

The docking station is designed appropriately, looks quite good (though not just a designer piece) and processed appears good. The HD2 is easy to insert and remove and clean sitting in the leadership of the docking station. Both synchronization and charging (with the power supply unit) are working properly (in use for a few weeks).
Criticism: In the scarce German manual is especially pointed out that the docking station must not be simultaneously connected to the PC and the power supply unit. But finds a small slide switch, which allows you to choose between "Sync" and "Charge" on the front page. This switch is not mentioned in the documentation, and it remains unclear whether the information in the guide therefore fall away.
I have not yet dared to join actually charger and PC at the same time and switch to the front desk. If this works, it would be of course the best solution.
Even explaining: When synchronization connection via USB to the PC, the HD2 is also loaded, but the charge time significantly longer than when charged with the power supply.