diff --git a/stepmania/src/StreamDisplay.cpp b/stepmania/src/StreamDisplay.cpp
index 598e66a3d4..800d120597 100644
--- a/stepmania/src/StreamDisplay.cpp
+++ b/stepmania/src/StreamDisplay.cpp
@@ -1,7 +1,20 @@
 #include "global.h"
 #include "StreamDisplay.h"
 #include "GameState.h"
+#include <float.h>
 
+StreamDisplay::StreamDisplay()
+{
+	m_fMeterHeight = 1;
+	m_fMeterWidth = 1;
+	m_iNumStrips = 1;
+	m_iNumChambers = 1;
+	m_fPercent = 0;
+	m_fTrailingPercent = 0;
+	m_fVelocity = 0;
+	m_fPassingAlpha = 0;
+	m_fHotAlpha = 0;
+}
 
 void StreamDisplay::Load( 
 	float fMeterWidth, 
@@ -111,7 +124,18 @@ void StreamDisplay::DrawPrimitives()
 
 void StreamDisplay::SetPercent( float fPercent )
 {
-	ASSERT( fPercent >= 0.0f && fPercent <= 1.0f );
+	DEBUG_ASSERT( fPercent >= 0.0f && fPercent <= 1.0f );
+	if( _isnan(fPercent) )
+	{
+		DEBUG_ASSERT_M( 0, "fPercent is NaN" );
+		fPercent = 1;
+	}
+	if( !_finite(fPercent) )
+	{
+		DEBUG_ASSERT_M( 0, "fPercent is infinite" );
+		fPercent = 1;
+	}
+
 	float fDeltaPercent = fPercent - m_fPercent;
 	m_fVelocity += fDeltaPercent;
 	m_fPercent = fPercent;
diff --git a/stepmania/src/StreamDisplay.h b/stepmania/src/StreamDisplay.h
index 8e4e67e4ef..6afe19d2fa 100644
--- a/stepmania/src/StreamDisplay.h
+++ b/stepmania/src/StreamDisplay.h
@@ -7,16 +7,7 @@
 class StreamDisplay : public Actor
 {
 public:
-	StreamDisplay()
-	{
-		m_fMeterWidth = 0;
-		m_fMeterHeight = 0;
-		m_iNumStrips = 1;
-		m_iNumChambers = 1;
-		m_fPercent = 0;
-		m_fPassingAlpha = 0;
-		m_fHotAlpha = 0;
-	}
+	StreamDisplay();
 
 	virtual void Update( float fDeltaSecs );
 
diff --git a/stepmania/src/global.h b/stepmania/src/global.h
index a0b084546b..118def675b 100644
--- a/stepmania/src/global.h
+++ b/stepmania/src/global.h
@@ -110,9 +110,11 @@ void ShowWarning( const char *file, int line, const char *message ); // don't pu
 #define WARN(MESSAGE) (ShowWarning(__FILE__, __LINE__, MESSAGE))
 
 #ifdef DEBUG
-#define DEBUG_ASSERT(x)	ASSERT(x)
+#define DEBUG_ASSERT(x)		ASSERT(x)
+#define DEBUG_ASSERT_M(x,y)	ASSERT_M(x,y)
 #else
 #define DEBUG_ASSERT(x)
+#define DEBUG_ASSERT_M(x,y)
 #endif
 
 /* Define a macro to tell the compiler that a function has printf() semantics, to