diff --git a/projects/VC90/FlightGear/FlightGear.vcproj b/projects/VC90/FlightGear/FlightGear.vcproj
index 58633d244..364454c1b 100644
--- a/projects/VC90/FlightGear/FlightGear.vcproj
+++ b/projects/VC90/FlightGear/FlightGear.vcproj
@@ -385,14 +385,6 @@
 				RelativePath="..\..\..\src\Aircraft\controls.hxx"
 				>
 			</File>
-			<File
-				RelativePath="..\..\..\src\Aircraft\replay.cxx"
-				>
-			</File>
-			<File
-				RelativePath="..\..\..\src\Aircraft\replay.hxx"
-				>
-			</File>
 			<File
 				RelativePath="..\..\..\src\Aircraft\flightrecorder.cxx"
 				>
@@ -401,6 +393,14 @@
 				RelativePath="..\..\..\src\Aircraft\flightrecorder.hxx"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\src\Aircraft\replay.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\Aircraft\replay.hxx"
+				>
+			</File>
 		</Filter>
 		<Filter
 			Name="Lib_Airports"
@@ -2525,6 +2525,38 @@
 				RelativePath="..\..\..\src\GUI\dialog.hxx"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGColor.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGColor.hxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGFontCache.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGFontCache.hxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGPUIDialog.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGPUIDialog.hxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGPUIMenuBar.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\GUI\FGPUIMenuBar.hxx"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\src\Gui\fonts.cxx"
 				>
@@ -3753,6 +3785,14 @@
 				RelativePath="..\..\..\src\Instrumentation\mrg.hxx"
 				>
 			</File>
+			<File
+				RelativePath="..\..\..\src\Instrumentation\NavDisplay.cxx"
+				>
+			</File>
+			<File
+				RelativePath="..\..\..\src\Instrumentation\NavDisplay.hxx"
+				>
+			</File>
 			<File
 				RelativePath="..\..\..\src\Instrumentation\navradio.cxx"
 				>
@@ -3777,14 +3817,6 @@
 				RelativePath="..\..\..\src\Instrumentation\od_gauge.hxx"
 				>
 			</File>
-			<File
-				RelativePath="..\..\..\src\Instrumentation\NavDisplay.cxx"
-				>
-			</File>
-			<File
-				RelativePath="..\..\..\src\Instrumentation\NavDisplay.hxx"
-				>
-			</File>
 			<File
 				RelativePath="..\..\..\src\Instrumentation\rad_alt.cxx"
 				>
diff --git a/src/GUI/FGColor.cxx b/src/GUI/FGColor.cxx
index e808af662..f96bb1331 100644
--- a/src/GUI/FGColor.cxx
+++ b/src/GUI/FGColor.cxx
@@ -7,6 +7,7 @@
 #include <iostream>
 
 #include <simgear/props/props.hxx>
+#include <simgear/math/SGMath.hxx>
 
 ////////////////////////////////////////////////////////////////////////
 // FGColor class.