To fix contrast use the
FirmwareModify Tool it can be found here:
http://www.divshare.com/download/1633736-5f3
For the "horizontally inverted" problem edit your firmware using
s1res it can be found here:
http://www.divshare.com/download/1633858-72c
And for the volume menu problem, follow the link on my first post.
Please read & understand those things.
Good Luck!!