The corner of scrolling views are not drawn with the system colour. Here is a patch to fix it: Index: nsScrollingView.cpp =================================================================== RCS file: /cvsroot/mozilla/view/src/nsScrollingView.cpp,v retrieving revision 3.72 diff -u -r3.72 nsScrollingView.cpp --- nsScrollingView.cpp 1998/12/15 05:47:25 3.72 +++ nsScrollingView.cpp 1998/12/18 17:55:00 @@ -28,6 +28,7 @@ #include "nsViewsCID.h" #include "nsIScrollableView.h" #include "nsIFrame.h" +#include "nsILookAndFeel.h" static inline PRBool ViewIsShowing(nsIView *aView) @@ -42,6 +43,8 @@ static NS_DEFINE_IID(kIScrollableViewIID, NS_ISCROLLABLEVIEW_IID); static NS_DEFINE_IID(kWidgetCID, NS_CHILD_CID); static NS_DEFINE_IID(kIViewIID, NS_IVIEW_IID); +static NS_DEFINE_IID(kLookAndFeelCID, NS_LOOKANDFEEL_CID); +static NS_DEFINE_IID(kILookAndFeelIID, NS_ILOOKANDFEEL_IID); //---------------------------------------------------------------------- @@ -257,7 +260,13 @@ if (clipres == PR_FALSE) { - rc.SetColor(NS_RGB(192, 192, 192)); + nscolor bgColor = NS_RGB(192,192,192); + nsILookAndFeel * lookAndFeel; + if (NS_OK == nsRepository::CreateInstance(kLookAndFeelCID, nsnull, kILookAndFeelIID, (void**)&lookAndFeel)) { + lookAndFeel->GetColor(nsILookAndFeel::eColor_WidgetBackground, bgColor); + } + + rc.SetColor(bgColor); rc.FillRect(brect); if (PR_TRUE == mShowQuality)

thanks michael. i've added in your fix in slightly modified form. the change prevents resource leaks and unnecessary memory thrashing.