This change is required three times in Class TRBtn (Buttons for the RibbonBar) to properly show the popup menus on XP:
On Windows 7 it was working fine but failed on XP. Now it is ok
   ::oPopup:Activate( ::nTop + ::nHeight(), ::nLeft - oWnd:nLeft, oWnd, .f. )On Windows 7 it was working fine but failed on XP. Now it is ok