LoTROInterface - RoR UI elements

This is still in project, not finalised but i am stuck on a little graphic glitch, probably a panel and i dont understand what it could be.

As you can see, there is on the 3 panels a strange border (i pointed it out with the red arrow).

I must say that i am at a loss. I tried to remove some panels, to change them, no way.

For a better research i put mainly every panel on transparency (as a temporary try)... but yet this inside border is still there.

Here the list of all the art assets i found

Code:

          <Mapping ArtAssetID="Mount_Appear_Background" FileName="mount\Mount_Appear_Background.tga"></Mapping>

        <Mapping ArtAssetID="Mount_TraitTree_Background2" FileName="mount\Mount_TraitTree_Background21.tga"></Mapping>

        <Mapping ArtAssetID="Mount_TraitTree_Background2_Heavy" FileName="mount\Mount_TraitTree_Background21.tga"></Mapping>

        <Mapping ArtAssetID="Mount_TraitTree_Background2_Medium" FileName="mount\Mount_TraitTree_Background21.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_IconBase" FileName="mount\MountedCombatStats_IconBase.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_LevelupBaseHorse_Heavy" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_LevelupBaseHorse_Light" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_LevelupBaseHorse_Medium" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_TitleBase_Heavy" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_TitleBase_Light" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_TitleBase_Medium" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsBase" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsBase_NoPointBoxes" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonmount_base_large" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsMTX" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsMTX_Ghost" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsMTX_Press" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_PointsMTX_Roll" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_slotFloatingBaseDeco" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_slotFloatingBaseDeco_Heavy" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="buttonMount_slotFloatingBaseDeco_Medium" FileName="invisible.tga"></Mapping>

          <Mapping ArtAssetID="wizard_base" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="Mount_BarCatagory" FileName="invisible.tga"></Mapping>

          

        

        <Mapping ArtAssetID="Mounted_Combat_Color_Swatch_BG_Body" FileName="mount\Mounted_Combat_Color_Swatch_BG_Body.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_Color_Swatch_BG_Feet" FileName="mount\Mounted_Combat_Color_Swatch_BG_Feet.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_Color_Swatch_BG_Head" FileName="mount\Mounted_Combat_Color_Swatch_BG_Head.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_Color_Swatch_BG_Hide" FileName="mount\Mounted_Combat_Color_Swatch_BG_Hide.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_Color_Swatch_BG_Tail" FileName="mount\Mounted_Combat_Color_Swatch_BG_Tail.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_LevelUp_Shield_Background" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="Mounted_Combat_Stats_Meter" FileName="mount\Mounted_Combat_Stats_Meter.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_Background" FileName="invisible.tga"></Mapping>

        <Mapping ArtAssetID="MountedCombatStats_IconBase" FileName="mount\MountedCombatStats_IconBase.tga"></Mapping>

Also, it seems there is a little bug within the ROR Pack skindefinition concerning the Mounted_Combat_Color_Swatch_BG_Body. Without any size coding, i just made a sort of duplicata of the originals assets, BUT this does not match really in size ....with the new modele i made. More, the Mounted_Combat_Color_Swatch_BG_Tail asset show as if the color box for the tail was below the box, but in game it is above the box ....

So if you have an idea ... let me know

Thank you