I made my own skin for the installer with skin builder. Everything works fine in XP but if I need to pop up a message box I have a problem with 7.
I put the link to an image showing the problem. What I have missed in my skin? Message box should be uniform in its color. no with the button background white. And this problem appears only in 7
Win 7 MessageBoxes consist from two parts: Upper one [black on your picture] and lower one with buttons.
The lower one could not be skinned with skinbuilder.
Maybe the SkinBuilder team will add this feature in some new version.