jQuery Mobile Checkbox Fieldset (Data-Type-Horizontal) icon bug (not hidden?)

So I'm using jQuery Mobile's ability to display checkboxes horizontally with the fieldset property Data-Type="Horizontal"; however, even though all the checkbox icons are supposed to be hidden, one of them appears to be fighting its way through to the surface, as seen here with the Landmine choice:

Why is this happening?

<!--Mechanism of Injury-->
<label id="tcInjuryMechLabel" for="tcInjuryMech">
    <h3 id="tcInjuryMechHdr" class="headers">
        Mechanism of Injury: (Choose all that apply)
    </h3>
</label>
<fieldset id="tcInjuryMech" data-role="controlgroup" data-type="horizontal">
    <label id="tcInjuryMechOp1Label" for="tcInjuryMechOp1">
        Artillery
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp1" value="Artillery">

    <label id="tcInjuryMechOp2Label" for="tcInjuryMechOp2">
        Blunt
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp2" value="Blunt">

    <label id="tcInjuryMechOp3Label" for="tcInjuryMechOp3">
        Burn
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp3" value="Burn">

    <label id="tcInjuryMechOp4Label" for="tcInjuryMechOp4">
        Fall
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp4" value="Fall">

    <label id="tcInjuryMechOp5Label" for="tcInjuryMechOp5">
        Grenade
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp5" value="Grenade">

    <label id="tcInjuryMechOp6Label" for="tcInjuryMechOp6">
        GSW
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp6" value="GSW">

    <label id="tcInjuryMechOp7Label" for="tcInjuryMechOp7">
        IED
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp7" value="IED">

    <label id="tcInjuryMechOp8Label" for="tcInjuryMechOp8">
        Landmine
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp8" value="Landmine">

    <label id="tcInjuryMechOp8Label" for="tcInjuryMechOp8">
        MVC
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp8" value="MVC">

    <label id="tcInjuryMechOp9Label" for="tcInjuryMechOp9">
        RPG
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp9" value="RPG">

    <label id="tcInjuryMechOp10Label" for="tcInjuryMechOp10">
        Other (Specify Below)
    </label>
    <input type="checkbox" name="tcInjuryMechOp[]" id="tcInjuryMechOp10" value="Other" onchange="enableOtherMech();">
</fieldset>
<div id="tcInjuryMechOtherDiv">
    <input type="text" name="tcInjuryMechOther" id="tcInjuryMechOther"  placeholder="Other(Specify)" disabled>
</div>