Hi,
i just updated my atlas with an updated version of a transparent icon (PSD) and it stopped being transparent (it was before).
I re exported the icon as PNG and tried again with same results.
I updated to 3.0.6f7 with no difference.
If i add the same icon (PSD or PNG) as unity GUITexture it shows transparent.
All the other icons (not modified) are transparent and ok.
(I can't attach any psd file to this post

)
Any tips?