Попробуйте следующее. Это потому, что заполнитель пустая строка. Просто добавьте td
в нем.
JSFiddle
HTML
<table id="songList">
<thead>
<tr>
<th id="check"><input type="checkbox" title="Select All"></th>
<th id="delete"><button title="Delete Selected"></button></th>
<th id="play"><button></button></th>
<th id="artist" style="width: 296px; ">Artist</th>
<th id="title" style="width: 296px; ">Title</th>
<th id="album" style="width: 297px; ">Album</th>
</tr>
</thead>
<tbody style="height: 204px; " class="ui-sortable"><tr class="ui-state-default playing"><td class="check"><input type="checkbox"></td><td class="delete"><button title="Delete From List"></button></td><td class="play"><button></button></td><td class="artist" style="width: 296px; ">Masakazu Sugimori</td><td class="title" style="width: 296px; ">Ace Attorney ~ Prologue</td><td class="album" style="width: 280px; ">Phoenix Wright - Ace Attorney OST</td></tr><tr class="ui-state-default"><td class="check"><input type="checkbox"></td><td class="delete"><button title="Delete From List"></button></td><td class="play"><button></button></td><td class="artist" style="width: 296px; ">Masakazu Sugimori</td><td class="title" style="width: 296px; ">Reminiscence ~ Case DL-6</td><td class="album" style="width: 280px; ">Phoenix Wright - Ace Attorney OST</td></tr><tr class="ui-state-default"><td class="check"><input type="checkbox"></td><td class="delete"><button title="Delete From List"></button></td><td class="play"><button></button></td><td class="artist" style="width: 296px; ">Masakazu Sugimori</td><td class="title" style="width: 296px; ">Rise From The Ashes ~ End</td><td class="album" style="width: 280px; ">Phoenix Wright - Ace Attorney OST</td></tr></tbody>
</table>
CSS
table input[type=checkbox], table button {
border: none;
margin: 0;
padding: 0;
width: 13px;
height: 13px;
position: relative;
top: 1px;
}
table {
border-spacing: 0;
width: 100%;
}
JS
$('#songList tbody').sortable({
refreshPositions: true,
opacity: 0.6,
scroll: true,
containment: 'parent',
placeholder: 'ui-placeholder',
tolerance: 'pointer',
'start': function (event, ui) {
ui.placeholder.html("<td colspan='6'></td>")
}
}).disableSelection();