The Difference Engine makes s appear where they shouldn't, causing e.g. the following markup:
<tr>
<td class="diff-blockheader" colspan="2">Line 11:</td>
<td class="diff-blockheader" colspan="2">Line 11:</td>
</tr>
This also results in bigger spacing on top of the diff table.
I fixed part of that issue a while ago in
https://github.com/splitbrain/dokuwiki/commit/5048c277bbf430c50bf87cd17ef1e5e21fcb095a but there are still some problems left which I couldn't find.