[jQuery] Odd overlap issue with cycle plugin

[littlerobothead]

I have a slideshow set up here, for reference:

http://www.littlerobothead.com/secret.php

You'll be able to see the slides as they overlap when using the "next"
or "previous" buttons. The CSS that controls the slides themselves
is:

#top-feature { /* this is the parent container */
        height: 300px;
        padding: 20px 0 0 0;
        border-bottom: 2px solid #452219;
        background: url('/images/1.jpg') top left repeat;
        overflow: hidden;
}

.slide { /* this is the child class for slides */
        width: 700px;
        margin: 30px;
        padding: 20px;
        background: url('/images/darkbrown-80.png') top left repeat;
        height: 220px;
        float: left;
        border-bottom: 1px solid #320104;
}

I believe I've satisfied the requirements of the plugin (i.e. fixed
height and width for slides, overflow hidden on parent container). To
be clear, it works just fine with any fx method other than
"scrollHorz" or "scrollVert"; in both, the slides overlap at the top
or bottom as they transition. I'm sure I'm missing something simple.
I've tried a bit of tweaking on the CSS itself, but nothing changes.
Any ideas? Thanks all.