The files were identified using the pngcrush software and repaired by stripping out the PNG header including the ICC profile using the command: $ pngcrush -fix -force old.png new.png; mv -f new.png old.png Each file was manually checked in an image viewer to look for any corruptions. This follows from the threads http://thread.gmane.org/gmane.games.flightgear.devel/79895 and http://thread.gmane.org/gmane.games.flightgear.devel/79898 .
