1. View any skin where tabs are defined (VitreousBlue, Blue Glass, 7on, LastFM, etc.)
2. View -> Properties
2. Bring mouse over "Basic tab". Notice that with mouse over it the tab matches all the other tabs.
This is with the mouse over the Details tab:

This is the properties dialog when first opened. Everything is fine here:

This is the same properties dialog but now the mouse is over the over the Basic tab (I thought since this tab is already opened the bitmap should not change):

http://www.ventismedia.com/mantis/view.php?id=5987