Rockbox

Compared to the level of the original Iriver firmware, and compared to the playback level of hard drive playback, the playback level of the FM receiver is much too low. My eas has been classically trained for 35 years, and I use a high-grade headphone (AKG 240 Studio, 55 Ohms). I guess the difference is more than 12 dB. Example: When listening to a piece of music from hard drive, recorded a full level, setting the volume level to 2/3 of max., it plays very loud, and setting the playback level to max. almost blows my ears out. With the FM receiver active, I have to set the volume to max all the time, and it is still not loud enough for some stations. It is also my impression that the sensitivity of the receiver runnung Rockbox is lower. But because at frequency modulation, the output level does not depend on the HF input level, I don't think that those two observations correlate. Maybe the registers of the FM receiver chip are setup differently, compared to the Iriver firmware?
PS. I am using the Rockbox built August 31 2006, my firmware is 1.66.
Horst