Missing some content on last part of the div.

[naughty-dog]

Sorry before for my bad English,
I had a little problem here that i cannot solved by my self, honestly I already stacked on this for almost a week.
Here's my HTML code

<div class="thumbImgContainer">
    <a href="javascript:somelinkusingscript"><img src="./img/#1" /></a>
    <a href="javascript:somelinkusingscript"><img src="./img/#2" /></a>
    <a href="javascript:somelinkusingscript"><img src="./img/#3" /></a>
    <a href="javascript:somelinkusingscript"><img src="./img/#4" /></a>
    <a href="javascript:somelinkusingscript"><img src="./img/#5" /></a>
    <a href="javascript:somelinkusingscript"><img src="./img/#6" /></a>
       ...
</div>

And here's my js (no options actually)

$(".thumbImgContainer").smoothDivScroll();

This is my CSS

.overlayGallery .thumbImgContainer {
    position: absolute;
    width: 100%;
    height: 80px;

    overflow: hidden;

    bottom: 0;
    left: 0;

    text-align: center;

    background-color: #000;
    background-color: rgba(0,0,0,.8);

    -webkit-transition: all .3s ease-out;
    -moz-transition: all .3s ease-out;
    -o-transition: all .3s ease-out;
    transition: all .3s ease-out;
}

.overlayGallery .thumbImgContainer a img {
    height: 74px;
    width: 131px;
    opacity: .4;
    margin: 3px 2px;

    -webkit-transition: all .3s ease-out;
    -moz-transition: all .3s ease-out;
    -o-transition: all .3s ease-out;
    transition: all .3s ease-out;
}

.overlayGallery .thumbImgContainer a:hover img,
.overlayGallery .thumbImgContainer a#current img {
    opacity: 1;
}

Otherwise, I'm using jQuery SmoothDivScroll 1.3 CSS and JS (no modification) and also jQuery 1.10.2 as well.

My problem was, as you see on html code, there would be so many images i included there (using php query from db - don't know if this has relevance to the problem).
But the 'last' content ( for example, img#6 ) won't showed, it's just showed until img#5.
When I inspect element, it's showed, but somehow it's alone placed on the bottom of the other, yet my div overflow hidden.
Hope you could understand what I mean, and could fix my problem.
Thanks so much ..