New Star Soccer 4

SimonH, I'm getting some issues with collisions between the ball and the goalpost/crossbar. Basically I handle the collision like so...

If matchengine.enginestatus <> CENGINESTATUS_REPLAYING	' Don't do collisions during replays
			Local bounce:Float = 0.0
			Local NFx:Float = 0.0
			Local NFy:Float = 0.0
			Local NFz:Float = 0.0
			
			For Local i:Int = 1 To CountCollisions(mesh)
				
				Local myentity:TEntity = CollisionEntity(mesh, i)	' TEntity
					
				' Get the normal of the surface which the entity collided with. 
				Local Nx# = CollisionNX(mesh, i) 
				Local Ny# = CollisionNY(mesh, i) 
				Local Nz# = CollisionNZ(mesh, i) 
				
				' Compute the dot product of the entity's motion vector and the normal of the surface collided with. 
				Local VdotN# = vecVelocity.x*Nx# + vecVelocity.y*Ny# + vecVelocity.z*Nz#
				
				Select GetEntityType(myentity)
					Case CTYPE_GOALPOST
						Applog "Collision GoalPost"
						bounce = 0.8
						' Calculate the normal force. 
						NFx = -(2.0) * Nx# * VdotN# 
						NFy = -(2.0) * Ny# * VdotN# 
						NFz = -(2.0) * Nz# * VdotN#
						
						
					Case CTYPE_GOALNET
						Applog "Collision GoalNet"
						' Only bounce off net if post wasn't hit
						If bounce = 0 and (GetZ() > matchengine.GoalLine1 or GetZ() < matchengine.GoalLine2)
							NFx = -(2.0) * Nx# * VdotN# 
							NFy = -(2.0) * Ny# * VdotN# 
							NFz = -(2.0) * Nz# * VdotN# 
							
							'  Normal slight bounce
							bounce = 0.2
							EndIf
					Case CTYPE_WALL
						Applog "Collision Wall"
						If bounce = 0 
							bounce = 0.6
							NFx = -(2.0) * Nx# * VdotN# 
							NFy = -(2.0) * Ny# * VdotN# 
							NFz = -(2.0) * Nz# * VdotN# 
						EndIf
						
					Case CTYPE_STADIUM
						Applog "Collision Stadium"
						If bounce = 0 
							bounce = 0.6
							NFx = -(2.0) * Nx# * VdotN# 
							NFy = -(2.0) * Ny# * VdotN# 
							NFz = -(2.0) * Nz# * VdotN# 
						EndIf
				End Select
				
			Next
			
			If bounce > 0
				Local mx:Float  = ((vecVelocity.x + NFx#) * bounce)
				Local my:Float  = ((vecVelocity.y + NFy#) * bounce)
				Local mz:Float  = ((vecVelocity.z + NFz#) * bounce)
				
				vecVelocity.x = mx
				vecVelocity.y = my
				vecVelocity.z = mz
			EndIf
		EndIf

The bounce check is purely to try to force the game to deal with primarily the goalpost collision in one loop rather than deal with a clash between ball, goalpost and goalnet.
However, I'm occasionally seeing the ball change direction two or three times in one collision with the goal frame.