Failure to display content produced in earlier version

The following content, which was produced and displayed fine in 2.X, doesn't in 3.5.2:

<div class=\"buttons\" style=\"float: right;\">
<ul>
    <li><a href=\"/fr/path/path\"><span>BLA BLA BLAH</span></a></li>
</ul>
</div>

I have been able to reproduce this issue in your Demo page editors, too.

More precisely, this content fails to be displayed in FF4, IE9 and Chrome Stable, but it's displayed fine in Safari (Win) and Opera11. I believe it worked well in FF3.X last week.

FF4 shows the following Javascript error:

regular expression too complex

Note that FF4 comes with a new Regex engine.