texture dilation filter - need HELP!

i' m implementing real time skin rendering using lightmap blurring like in ATI Ruby demo, i have found presentation slides from GDC 04-05, and a chapter in GPU gems1 about that http://ati.amd.com/developer/gdc/Gosselin_skin.pdf http://ati.amd.com/developer/siggraph04/Sander_SkinSketch.pdf and discussed in thread http://www.beyond3d.com/forum/archive/index.php/t-10661.html here is UV parametrization of the mesh( it is not perfect ) pic1: http://img470.imageshack.us/my.php?image=uvheadmapsg2.jpg alpha channel of a texture used in blur shader to know where sampling outside boundaries pic2: http://img213.imageshack.us/my.php?image=alphavp8.jpg my problems come after blurring lightmap: due to large filter kernel 9x9 and subsequent blur pass, texture seams become evident (black eyes and mouth countours) pic3: http://img206.imageshack.us/my.php?image=blutlightmapvr4.jpg relevant code snippet of lightmap computation fragment shader alphaMap is pic2

gl_FragColor.rgb = AshikShirDiff(NdotL, dot(N, V), lightColor );
 gl_FragColor.a = texture2D(alphaMap, gl_TexCoord[0].st).a; //1 outside texture boundaryes

blurring fragment shader(vertical same as horizontal): skinSamp1 is the light map

vec4 weight[5] = {
        {0.021, 0.0, 0.0, 1.0},
        {0.07, 0.0, 0.0, 1.0},
        {0.13, 0.086, 0.086, 1.0},
        {0.179, 0.244, 0.244, 1.0},
        {0.2, 0.33, 0.33, 1.0},
    };


vec4 mainCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s,gl_TexCoord[0].t)) * weight[4];
    vec4 OutCol = mainCol;
    float flag = OutCol.a;
    
    vec4 currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s+ TexelIncrement * 4.0,gl_TexCoord[0].t)) * weight[0];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;

    currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s+ TexelIncrement * 3.0,gl_TexCoord[0].t)) * weight[1];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;
 
     currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s+ TexelIncrement * 2.0,gl_TexCoord[0].t)) * weight[2];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;
        
    currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s+ TexelIncrement * 1.0,gl_TexCoord[0].t)) * weight[3];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;    
  
     currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s- TexelIncrement * 1.0,gl_TexCoord[0].t)) * weight[3];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;

     currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s- TexelIncrement * 2.0,gl_TexCoord[0].t)) * weight[2];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;
        
    currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s- TexelIncrement * 3.0,gl_TexCoord[0].t)) * weight[1];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;
    
    currCol = texture2D(skinSamp1, vec2(gl_TexCoord[0].s- TexelIncrement * 4.0,gl_TexCoord[0].t)) * weight[0];
    OutCol += currCol ;
    flag = max(flag, currCol.a);
    if (currCol.a < mainCol.a)
        mainCol = currCol;
 
   if (flag == 1.0)
        gl_FragColor = vec4(mainCol.xyz, 1.0);
    else gl_FragColor = vec4(OutCol.xyz, 0.0);

i implemented dilation filter like explained in ATI presentation but with wrong result. alphaMap is same resolution of lightMap any ideas to remove these artifacts due to several blurring pass? thanks