Android 2.1 camera preview error

I have a problem with using the camera of an Android 2.1 phone (HTC Desire), maybe you can help me. After calling camera.open() DDMS in Eclipse shows the following errors:

ERROR/MediaPlayerService(30):   error: -2
ERROR/MediaPlayer(30): Unable to to create media player
ERROR/CameraService(30): Failed to load CameraService sounds.

Test view in the emulator works fine, but on my phone only a po开发者_运维问答pup is shown where I only can close the application.