Source View Creating Duplicate Tags

I have FCKEditor 2.6.5 in a ColdFusion page.

When I click on Source, it's adding extra tags to my content. Each time I toggle back/forth from Design to Source, more duplicate tags are inserted. Keep going, I can have infinite number of duplicate tags. It seems to appear inside tables, in last column! The first two table cells in the same row are never impacted!

Original HTML snippet:
<tr>
<td width="33%">
<div><b>Planning</b></div>
</td>
<td width="33%">
<div><b>CO Engineering</b></div>
</td>
<td width="33%">
<div><b>OSP</b> Engineering</div>
</td>
</tr>
Click Source, and extra <b> tags appear in last cell:
<tr>
<td width="33%">
<div><b>Planning</b></div>
</td>
<td width="33%">
<div><b>CO Engineering</b></div>
</td>
<td width="33%">
<div><b><b>OSP</b> Engineering</b></div>
</td>
</tr>
<tr>

I've set these value in the config, which might be important:
- FCKConfig.DocType = '<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">' ;
- FCKConfig.ProtectedTags = 'b|br|div|span|style|td|tr' ;
- FCKConfig.FormatSource = true ;
- FCKConfig.FormatOutput = false ;
- FCKConfig.EnterMode to <div> because the default <p> value was adding <p> tags inside of table cells, which is invalid.