Hi,
The US and the European software version are not compatible at the moment. This means you can only change from one to the other by erasing your configuration file (devices, activities).
The procedure to do this is described on the Philips website, I will give it here again:
- Switch off the RC9800i with the button on the back
- Switch on the RC9800i with the button on the back and immediately press the HOME and PAGE buttons simultanuously. Keep both buttons pressed until the "waiting for firmware upgrade..." screen appears. Please mind: the buttons need to be pressed immediately after switching on the device and it will take a few seconds before the screen appears.
- Connect the RC9800i to the PC with the USB cable.
- Start the Firmware Upgrade Tool and follow the instructions on the PC screen.

This will solve the problem.

Kind regards
Philips support RC9800i