On random occasions, the Seashell Spotter game asks me to compare a blank image to two other seashells(the white bony ones, to be precise). It also draws two blanks below them(which I assume are supposed to be the other two shells), but I can't click those. This makes it impossible to get multiple shells in a row for the achievements.

I have Windows 7 64-bit and I use Firefox.

This has been reported here: Glade Dress?. :)