Testing Rapiro (equipped with Raspberry pi b+, camera and audio amplifier) he suddenly showed a strange behavior. Powering on, the servos didn't get initialized. The reason of this problem was too less power from the accumulators (as mentioned in an older thread. Perhaps it would be nice to implement a voltage control (I will think about it). Btw. to get espeak working from the cgi-script, you have to add www-data (apache 2 group) both to group audio and video. Don't no why, but now it works.