I am also having the same problem.. I get the same errors when using an ICO file that works perfectly everywhere but on my newly installed Ubuntu machine.
Looking at the screenshot in post 6 I actually get failures in all locations including nautilus.. (the preview is just a black square in nautilus)
There does appear to be something weird with EOG not reading ICO files properly.
I am also having the same problem.. I get the same errors when using an ICO file that works perfectly everywhere but on my newly installed Ubuntu machine.
Looking at the screenshot in post 6 I actually get failures in all locations including nautilus.. (the preview is just a black square in nautilus)
There does appear to be something weird with EOG not reading ICO files properly.