Memory leak or defective programmer ?

try this:

Type TestBall
	Field BallEntity:Tentity

It is always good practice to explicitly type the objects. The Freeentity command is looking for a Tentity.

I would *highly* recommend using strict or superstrict while coding in blitzmax. It forces you to declare stuff but makes for much cleaner and easier to debug code. Here is your example using strict.

freeentity now removes the mesh and frees the memory. (I commented out the texture stuff so i could run it without your media, don't really need it for this test)

'Import sidesign.minib3d
Import "minib3d.bmx"
Strict

Local width=640,height=480,depth=16,mode=0

Graphics3D width,height,depth,mode

Local cam:Tentity =CreateCamera()
PositionEntity cam,0,0,-10

Local light:Tentity =CreateLight(1)
Local MrBall:TestBall

'Global tex:TTexture =LoadTexture("examples\media\test.png")

Global BallList:TList=CreateList()

;' used by camera code
Local mxs#=0
Local mys#=0
Local move#=0.5
MouseXSpeed() ;' flush
MouseYSpeed() ;' flush

;' used by fps code
Local old_ms=MilliSecs()
Local renders:Int
Local fps:Int

While Not KeyDown(KEY_ESCAPE)		

	If KeyHit(KEY_ENTER) Then DebugStop

	;'' control camera
	
	;' mouse look
	
	If KeyDown(KEY_SPACE)=False
	
		mxs#=mxs#+(MouseXSpeed()/5.0)
		mys#=mys#+(MouseYSpeed()/5.0)
	
		RotateEntity cam,mys#,-mxs#,0
	
		MoveMouse width/2,height/2
	
	EndIf
	
	If KeyDown(Key_1) Then
		TestBall.Add
		FlushKeys
	EndIf

	If KeyDown(Key_2) Then
		If CountList(BallList) > 0 Then
			For MrBall = EachIn BallList
				'Sloppy way to get last Ball
			Next
			MrBall.Remove
			FlushKeys
		EndIf
	EndIf
	
	MouseXSpeed() ;' flush
	MouseYSpeed() ;' flush

	;' move camera forwards/backwards/left/right with cursor keys
	
	If KeyDown(KEY_UP)=True Then MoveEntity cam,0,0,move# ;' move camera forward
	If KeyDown(KEY_DOWN)=True Then MoveEntity cam,0,0,-move# ;' move camera back

	If KeyDown(KEY_LEFT)=True Then MoveEntity cam,-move#,0,0 ;' move camera left
	If KeyDown(KEY_RIGHT)=True Then MoveEntity cam,move#,0,0 ;' move camera right
	
	For MrBall = EachIn BallList
		MrBall.Spin
	Next
	
	RenderWorld
	renders=renders+1

	;' calculate fps
	If MilliSecs()-old_ms>=1000
		old_ms=MilliSecs()
		fps=renders
		renders=0
	EndIf
	
	Text 0,0,"FPS: "+fps
	Text 0,15,"Mem in Use: " + ((GCMemAlloced()) / 1000) + " KBs"
	Text 0,30,"Balls in World: "+CountList(BallList)

	Text 0,60,"Press 1 to Add a Ball"
	Text 0,75,"Press 2 to Remove a Ball"

	Flip

Wend
End

Type TestBall
	
	Field BallEntity:Tentity

	Function Add()
		Local obj:TestBall
		obj:TestBall = New TestBall
			obj.BallEntity=CreateSphere(24)
			PositionEntity obj.BallEntity,CountList(BallList)*3,0,0
			'EntityTexture obj.BallEntity,tex
		ListAddLast(BallList,obj:TestBall)			
	End Function
	
	Method Remove()
		FreeEntity BallEntity
		BallList.Remove Self
	End Method
	
	Method Spin()
		TurnEntity BallEntity,0.2,1,0.1
	End Method
	
End Type