When I use the right arrow key to fast forward through the song, I can go past the end of the song.
The right/bottom boundaries of transparency regions are one pixel off, always making the region smaller than it should be. While the main and equalizer windows are 275x116, the coords should go from (0,0) to (274,115), not (0,0) to (275,116). Classic 0..n-1 bug.
Transparency regions would be better implemented if you defined the limits of transparent space instead of the limits of viewable space.