error on repairing firmware 9.1.51

[rugarai3x]

I tried to extract the firmware of my mp4 last night using s1fwx tool. I had successfully extracted the firmware using extract.bat. However, when i was to repair the extracted firmware using repair.bat, i got an error saying my firmware file is unknown and got failed repairing the file. Is there other way to modify my firmware? I just want to change the theme of my mp4. Below is the mp4 firmware version. Thanks.

2006/12/28
9.1.51
2006/06/12
ACT2093_S75

[alex2pb]

Firmware above 9.0.43 cannot be extracted correctly .

[rugarai3x]

Is that so.. Thanks for the info. I hope a new released of that tool will comes out or other tools that others may recommend that can correctly extract firmwares you had said including mine.