sry for the late response, ofcourse the boot sound is enabled.
The original bootsound works if i backup it, but as soon i put my custom mp3 in the zip file it doesnt work anymore. The original file and my custom file have the same audioproperties (except from the bitrate wich is at 128kbit/s in my custom and at 160kbit/s in the original file).
btw. the docking sound doesnt work either, it is playable when i extract it from the phone but it doesnt work/play while docking/undocking (docking sound is the original file). I now checked again every possible setting in the phone but there is no option to de-/activate the docking sound.