font HASBOX problem

What is <font hasbox>?

[gcan]

I installed nicEdit on all my websites. It works fine, but from time to time I am getting support requests from users who cannot change font color. When I look at their texts I see the following:

<p hasbox="2">&nbsp;</p>
<p hasbox="2"><strong><font hasbox="2"><font size 3 hasbox="2"><font color><font hasbox="2">Profile text

What are "hasboxes" and what causes them? I searched the Google, but it doesn't give any results.