I'll try installing this on my Detritus installation, and will report back.
Edit: I installed this, and did the following example on my playground:
====== Sortable table ======
<sortable>
^ Town ^ Population ^
| Ayston | 2000 |
| Beeston | 5400 |
| Seaton | 1200 |
| Deesville | 8500 |
</sortable>
It worked immediately; sortable by both Town and Population columns. I didn't even clear the cache - it just worked.
I then did two side by side examples, one with surrounding <sortable> tags, and one without, to see if I could see any difference in the HTML:
Without <sortable>:
<div class="table sectionedit3"><table class="inline">
<thead>
<tr class="row0">
<th class="col0 leftalign"> Town </th><th class="col1 leftalign"> Population </th>
</tr>
</thead>
<tr class="row1">
<td class="col0 leftalign"> Ayston </td><td class="col1 leftalign"> 2000 </td>
</tr>
<tr class="row2">
<td class="col0 leftalign"> Beeston </td><td class="col1 leftalign"> 5400 </td>
</tr>
<tr class="row3">
<td class="col0 leftalign"> Seaton </td><td class="col1 leftalign"> 1200 </td>
</tr>
<tr class="row4">
<td class="col0 leftalign"> Deesville </td><td class="col1 leftalign"> 8500 </td>
</tr>
</table></div>
With <sortable>:
<div class="sortable"><div class="table sectionedit5"><table class="inline">
<thead>
<tr class="row0">
<th class="col0 leftalign"> Town </th><th class="col1 leftalign"> Population </th>
</tr>
</thead>
<tr class="row1">
<td class="col0 leftalign"> Ayston </td><td class="col1 leftalign"> 2000 </td>
</tr>
<tr class="row2">
<td class="col0 leftalign"> Beeston </td><td class="col1 leftalign"> 5400 </td>
</tr>
<tr class="row3">
<td class="col0 leftalign"> Seaton </td><td class="col1 leftalign"> 1200 </td>
</tr>
<tr class="row4">
<td class="col0 leftalign"> Deesville </td><td class="col1 leftalign"> 8500 </td>
</tr>
</table></div>
The closing </div> of the second example comes after some extra code for the section Edit button, but I think the key (only?) difference here is that the sortable table is wrapped inside an extra <div class="sortable">.
Does that show up in your example?