Wiki add extra empty div blocks at each edit

If I create wiki page, containing the following HTML text:

<ol>

<li>Something</li>

</ol>

Then save page and edit it. Page will appear as

<div class=indent style=margin-left: 15px;></div>

<ol>

<li>Something</li>

</ol>

[three new line characters]

If I save page again it will become:

<div class=indent style=margin-left: 15px;></div>

<div style=margin-left: 15px; class=indent></div>

<ol>

<li>Something</li>

</ol>

[six new line characters]

Every time I edit the page one div and three new line characters are added. If the page is more complicated (list have more elements), more emplty div blocks and more new line characters are added each time