all operating systems
Broken: 2.77 66552ca
Short description of error
Group instances do not take the "show_transparent" property into account. As a result, opaque members of a group may be occluded by translucent members. It dosn't happen every time as the drawing order depends by the group membership order, yet it may be a significant issue when using linked groups for character with glasses, or car with windows et cetera.
Internally, this is due to the dupli Base objects being temporary and therefore not able to be deferred to the transparency pass. A possible solution would be to draw only non transparent dupli members in the first pass, so that the transparent ones can be drawn afterwards.
A fix patch to help illustrating the issue
Exact steps for others to reproduce the error
A sample .blend file containing some grouped object and their group instance: the circle masks the monkey, but not the cube in the background when in material shading