Queried Virtual Shadow Maps problem

//vsmshadow_sm_helper2.hlsl

float4x4 m4x4_screen_to_shadowmap; // The uniform part of the transformation from screenspace to shadowmapspace


//-------------------------------------------------------------------------------------------------
// ScreenspaceToShadowmapspace
//-------------------------------------------------------------------------------------------------

inline float4 ScreenspaceToShadowmapspace(float screen_x, float screen_y, float z_view) 
{
	float4 v4_pos_screen_reprojected = float4( screen_x * z_view, screen_y * z_view, z_view, 1 );
	float4 v4_pos_lightspace	= mul(v4_pos_screen_reprojected, m4x4_screen_to_shadowmap);
	return v4_pos_lightspace;
};


//-------------------------------------------------------------------------------------------------
// ScreenspaceToShadowmapCoordinatesAndLightspaceDepth
//-------------------------------------------------------------------------------------------------

inline float3 ScreenspaceToShadowmapCoordinatesAndLightspaceDepth(float screen_x, float screen_y, float z_view) 
{
	float4 pos_light = ScreenspaceToShadowmapspace(screen_x, screen_y, z_view);

	// Project result into shadowmap coordinates

	double pos_light_w_inv = 1.0 / pos_light.w;

	float3 pos_shadowmap = 
		float3(
			0.5 + 0.5 * pos_light_w_inv * pos_light.x, // SM texture x
			0.5 - 0.5 * pos_light_w_inv * pos_light.y, // SM texture y 
			pos_light_w_inv * pos_light.z  // depth in SM space
		);

	return pos_shadowmap;
};

//vsmshadow_deferred.hlsl

//-------------------------------------------------------------------------------------------------
// PsApplySmTileToFramebufferUsingShadowDepthBuffer
// Apply shadow map tile to the frame buffer using the linear depth values stored in the
// Shadow Depth Buffer
//-------------------------------------------------------------------------------------------------

Ps_DEFAULT_OUT PsApplySmTileToFramebufferUsingShadowDepthBuffer(Ps_TC_IN IN)
{
	Ps_DEFAULT_OUT OUT;
	
	float shadow_term = 1.0f;
	const float shadow_ambient = 0.7f;
	//float shadow_ambient = UNIFORM_shadow_map_ambient;
	
	float z_view_center = tex2D(tex_shadow_depth_buffer, IN.v2_tc.xy).w;

	float3 pos_shadowmap = 
		ScreenspaceToShadowmapCoordinatesAndLightspaceDepth( IN.v2_tc.x, IN.v2_tc.y, z_view_center );
	float2 sm_coords = pos_shadowmap.xy;
	float depth_lightspace = pos_shadowmap.z;
	
	// Pixel lies on backplane or query does not concern current tile => Skip Fragment
	if(
		(z_view_center == 0.0f) ||  // skip pixels lying on the backplane (D3D9 only allows DWORDs for Clear, so we have to use 0 here).
		(sm_coords.x < 0) || (sm_coords.x > 1) ||  // pixel lies outside of current shdow map tile
		(sm_coords.y < 0) || (sm_coords.y > 1)
	) 
	{
		clip(-1);
	}

	
#if(1)

	shadow_term = (tex2D(tex_shadowmap_tile, sm_coords).x < (depth_lightspace)) ? shadow_ambient : 1.0f;

#else

	#include "vsmshadow_adaptive_sm_filtering_inc.hlsl"

#endif

	OUT.color = tex2D(tex_shadow_depth_buffer, IN.v2_tc.xy) * shadow_term;

	return OUT;
}