v18 - GetLabel() on image Control not working with special path

Ok, this is driving me crazy.
consider this piece of code:

            <control type="image">

                <include>mediaflags_large_layout</include>

                <texture>flags/flags_large/extras.png</texture>

                <visible>!String.Contains(Control.GetLabel(44444),blank)</visible>

                <visible>System.HasAddon(script.videoextras) + Window.IsVisible(Videos) + Container.Content(TVShows)</visible>

            </control>

and

        <control type="image" id="44444">

            <description>hidden image to verify if any extras exist</description>

            <posx>-100</posx>

            <posy>-100</posy>

            <width>1</width>

            <height>1</height>

            <texture fallback="blank.png">$INFO[ListItem.DBID,special://profile/addon_data/script.videoextras/tvshows/,.png]</texture>

            <visible>true</visible>

        </control>

but that doesn't work as expected, image flags/flags_large/extras.png is always there, when it should be just visible if a file, 25.png for example, exists in the addons user data.
i tried something more simpler then:

            <control type="image" id="112233">

                <texture fallback="blank.png">$INFO[ListItem.DBID,special://profile/addon_data/script.videoextras/tvshows/,.png]</texture>

                <visible>System.HasAddon(script.videoextras) + Window.IsVisible(Videos) + Container.Content(TVShows)</visible>

            </control>

            <control type="label">

                <width>auto</width>

                <posx>300</posx>

                <height>80</height>

                <aligny>center</aligny>

                <label>$INFO[Control.GetLabel(112233)]</label>

            </control>

And this is where the fun begins. The Image is shown as expected, if there is 25.png for show with id 25, it will be shown.
However, the coresponding debug label shows nothing at all. i tried to replace the texture again with flags/flags_large/extras.png, and here the debug label shows the path as expected.
why is that? Bug? or made i something stupid? Probably system dependend? (I am on windows 10, just in case that matters)