% file /usr/share/pixmaps/touchpad.png
/usr/share/pixmaps/touchpad.png: PNG image data, CORRUPTED,
Also, the icon does does not show up in the Preferences menu.
Opening it with eog gives errors as well.
thx for your report; this bug is also tracked upstream.
I fixed it in the devel branch and will update to F8 in a few days.