Hi Solcita
Robi only wakes up one time only after that you usually start him from the standing position.
Falling backward issues can be fixed by adding the white washers provided in stage 70 to the rear of Robi's feet but check that all screws are correctly tightened first and that all the D cuts joining the servos are correctly aligned.
Sometimes saying sit Robi is better than just sit.
You could try checking the connections to the eyes but you may have to replace them with new to get them working correctly.
Robi has to learn as you speak to him so try keeping your tone at an even level and talk slowly as he learns your voice tone he should improve over time. You could try a new SD card but it may make no difference.
Once Robi has woken up for the first time this is the only time you can input anything after that he can not be reprogramed.
Andy
Current builds:-C57,Zero, Lamborghini Countach, Caldercraft HMS Agamemnon,Robi,R2-D2, MFH Cobra .