Index: src/sdk/propgrid/src/propgrid/odcombo.cpp
===================================================================
--- src/sdk/propgrid/src/propgrid/odcombo.cpp    (revision 4091)
+++ src/sdk/propgrid/src/propgrid/odcombo.cpp    (working copy)
@@ -30,6 +30,7 @@
 #if wxUSE_COMBOBOX
 
 #ifndef WX_PRECOMP
+    #include "wx/app.h"
     #include "wx/log.h"
 
     #include "wx/button.h"
@@ -3091,7 +3092,13 @@
 
     if ( theme )
     {
+#if wxCHECK_VERSION(2, 8, 0)
         const bool isVista = (::wxGetWinVersion() >= wxWinVersion_6);
+#else
+        int Major = 0;
+        int family = wxGetOsVersion(&Major, NULL);
+        const bool isVista = ((family == wxWINDOWS_NT) && (Major >= 6));
+#endif
 
         if ( isVista )
             m_iFlags |= wxPGCC_BUTTON_STAYS_DOWN;
@@ -3354,7 +3361,13 @@
 
     if ( hTheme )
     {
-        const bool useVistaComboBox = ::wxGetWinVersion() >= wxWinVersion_6;
+#if wxCHECK_VERSION(2, 8, 0)
+        const bool useVistaComboBox = (::wxGetWinVersion() >= wxWinVersion_6);
+#else
+        int Major = 0;
+        int family = wxGetOsVersion(&Major, NULL);
+        const bool useVistaComboBox = ((family == wxWINDOWS_NT) && (Major >= 6));
+#endif
 
         RECT rFull;
         wxCopyRectToRECT(borderRect, rFull);