Click / Touch event Bug?

Problem: Bad click and touch event performance on s:Label.

I use the newest air version and Flash Builder 4.6 to develop a mobile app.

This is the code:

<s:Group horizontalCenter="10" top="200">
    <s:VGroup>
        <s:VGroup id="wortundtafelstriche">
            <s:HGroup id="wortalign" >
                <s:Label id="wort1" visible="false" textAlign="center" width="43" color="0xffffff"  />
                <s:Label id="wort2" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort3" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort4" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort5" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort6" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort7" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort8" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort9" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort10" visible="false" width="30" color="0xffffff"  />
                <s:Label id="wort11" visible="false" width="30" color="0xffffff"  />
            </s:HGroup>
            <s:HGroup id="tafelalign">
                <s:Image id="img"/>
            </s:HGroup>
        </s:VGroup>

        <s:Spacer height="10" width="100%" />
        <s:VGroup>
            <s:HGroup>
                <s:Label text="A" id="txt1" color="0xffffff"  width="60" height="40" click="makeunvisible(txt1),check(txt1.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="B" id="txt2" color="0xffffff"  width="60" height="40" click="makeunvisible(txt2),check(txt2.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="C" id="txt3" color="0xffffff"  width="60" height="40" click="makeunvisible(txt3),check(txt3.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="D" id="txt4" color="0xffffff"  width="60" height="40" click="makeunvisible(txt4),check(txt4.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="E" id="txt5" color="0xffffff"  width="60" height="40" click="makeunvisible(txt5),check(txt5.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="F" id="txt6" color="0xffffff"  width="60" height="40" click="makeunvisible(txt6),check(txt6.text)" />
            </s:HGroup>
            <s:Spacer height="15" width="100%" />
            <s:HGroup>
                <s:Label text="G" id="txt7" color="0xffffff"  width="60" height="40" click="makeunvisible(txt7),check(txt7.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="H" id="txt8" color="0xffffff"  width="60" height="40" click="makeunvisible(txt8),check(txt8.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="I" id="txt9" color="0xffffff"  width="60" height="40" click="makeunvisible(txt9),check(txt9.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="J" id="txt10" color="0xffffff"  width="60" height="40" click="makeunvisible(txt10),check(txt10.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="K" id="txt11" color="0xffffff"  width="60" height="40" click="makeunvisible(txt11),check(txt11.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="L" id="txt12" color="0xffffff"  width="60" height="40" click="makeunvisible(txt12),check(txt12.text)" />
            </s:HGroup>
            <s:Spacer height="15" width="100%" />
            <s:HGroup>
                <s:Label text="M" id="txt13" color="0xffffff"  width="60" height="40" click="makeunvisible(txt13),check(txt13.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="N" id="txt14" color="0xffffff"  width="60" height="40" click="makeunvisible(txt14),check(txt14.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="O" id="txt15" color="0xffffff"  width="60" height="40" click="makeunvisible(txt15),check(txt15.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="P" id="txt16" color="0xffffff"  width="60" height="40" click="makeunvisible(txt16),check(txt16.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="Q" id="txt17" color="0xffffff"  width="60" height="40" click="makeunvisible(txt17),check(txt17.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="R" id="txt18" color="0xffffff"  width="60" height="40" click="makeunvisible(txt18),check(txt18.text)" />
            </s:HGroup>
            <s:Spacer height="15" width="100%" />
            <s:HGroup>
                <s:Label text="S" id="txt19" color="0xffffff"  width="60" height="40" click="makeunvisible(txt19),check(txt19.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="T" id="txt20" color="0xffffff"  width="60" height="40" click="makeunvisible(txt20),check(txt20.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="U" id="txt21" color="0xffffff"  width="60" height="40" click="makeunvisible(txt21),check(txt21.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="V" id="txt22" color="0xffffff"  width="60" height="40" click="makeunvisible(txt22),check(txt22.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="W" id="txt23" color="0xffffff"  width="60" height="40" click="makeunvisible(txt23),check(txt23.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="X" id="txt24" color="0xffffff"  width="60" height="40" click="makeunvisible(txt24),check(txt24.text)" />
            </s:HGroup>
            <s:Spacer height="15" width="100%" />
            <s:HGroup>
                <s:Label text="Y" id="txt25" color="0xffffff"  width="60" height="40" click="makeunvisible(txt25),check(txt25.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="Z" id="txt26" color="0xffffff"  width="60" height="40" click="makeunvisible(txt26),check(txt26.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="Ä" id="txt27" color="0xffffff"  width="60" height="40" click="makeunvisible(txt27),check(txt27.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="Ö" id="txt28" color="0xffffff"  width="60" height="40" click="makeunvisible(txt28),check(txt28.text)" />
                <s:Spacer height="5" width="100%" />
                <s:Label text="Ü" id="txt29" color="0xffffff"  width="60" height="40" click="makeunvisible(txt29),check(txt29.text)" />
            </s:HGroup>

        </s:VGroup>

    </s:VGroup>
</s:Group>

The function of the click event:

protected function makeunvisible(obj:Object😞void
        {
            obj.visible = false;
        }

It is pretty simple.

If someone clicks on a letter (s:Label) the letter should be unvisible.

The frustating fact is that the method makeunvisible is not always called when I click on a letter.

Sometimes I have to click ten times before the method is called.

I also tried with touch events and there were no better results...

If I try it with the simulater on the desktop everything works fine but on the phone there is this strange behaviour.