It's IE9. I can run it in IE8 or IE7 Mode, and I get the same error.

 

Here is how you can reproduce the issue:

 

1. Open IE browser, and go to your CuteEditor's demo page http://cutesoft.net/example/general.aspx.

 

2. Switch to html mode, and replace the defult demo html markup with this:

 

<table style="padding-bottom: 0cm; margin: 0cm; padding-left: 0cm; padding-right: 0cm; font-family: Arial, , sansserif;background: rgb(51,51,153) repeat-x; padding-top: 0cm; moz-background-clip: -moz-initial; moz-background-origin: -moz-initial; moz-background-inline-policy: -moz-initial" border="0" cellspacing="0" cellpadding="0" width="100%" background="" bgcolor="#ffffff">
<tbody>
<tr>
<td valign="top" align="center"><!-- Table for display -->
<table border="0" cellspacing="0" cellpadding="0" width="600" bgcolor="#ffffff">
<tbody>
<tr>
<td width="600" align="center">
<div align="center">
<div align="center">
<div align="center">&nbsp;<img border="0" alt="" src="http://www.car-research.com/carinteractive/images/79/Car-ResearchHeaderBlue.jpg" width="600" height="117" /></div>
</div>
</div>
</td>
</tr>
<tr>
<td width="600" align="center"><!-- table of links -->
<table cellspacing="0" cellpadding="0" width="100%" bgcolor="#ffffff" align="center" images="" com="" www.car-research. carinteractive="" 257="" ibdctemplates="" background_nav.gif?="">
<tbody>
<tr>
<td><a href="http://www.car-research.com/"></a></td>
<td><a href="http://www.car-research.com/"></a></td>
<td><a href="http://www.car-research.com/"></a></td>
<td><a href="http://www.car-research.com/"></a></td>
<td><a href="http://www.car-research.com/"></a></td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td width="600" align="left"><strong><font size="2" face=""><font size="3"><span style="font-size: 10pt">
<div>
<table style="height: 188px" border="0" cellspacing="2" cellpadding="2" width="575" align="center">
<tbody>
<tr>
<td>
<p style="font-size: 8pt" align="left">
<div><span style="font-family: "><span style="font-size: 12pt"><span style="font-family: "><span style="font-family: Arial"><span style="font-family: "><span style="font-size: 12pt"><span style="font-family: ">Hello [firstname], </span></div>
<div></span></span></span></span></span></span>&nbsp;</div>
</td>
</tr>
</tbody>
</table>
</div>
<div align="center">&nbsp; </div>
<div align="center"></div>
<div align="center"></div>
<div></span></font></font><font size="2"><span style="font-family: "><span style="font-family: "></span></span></font></strong>&nbsp;</div>
</td>
</tr>
<tr>
<td width="600" align="center"><!-- table of links -->
<table cellspacing="0" cellpadding="0" width="100%" background="http://www.car-research.com/carinteractive/images/257/IBDCtemplates/background_nav.gif" bgcolor="#afafaf" align="center">
<tbody>
</tbody>
</table>
</td>
</tr>
<!--Hours footer -->
<tr bgcolor="#d9d4c1">
<td style="color: rgb(0,0,0); font-size: 12px" bgcolor="#ffffff" valign="middle" align="center">
<div>&nbsp;</div>
</td>
</tr>
<!--close of Hours footer --><!-- close Email footer -->
</tbody>
</table>
<!--close centering table --></td>
</tr>
</tbody>
</table>

Step 3: Switch back to "Normal" view, then do a CTRL-A and CTRL-C to copy all of it.

 

Step 4: Now open a new IE browser window, and then go to the cutesoft demo page again.

 

Step 5: Do a CTRL-A and CTRL-V to paste the content and you will see the error.

 

The key is to copy from "Normal" view and paste in to "Normal" view. I have tried it with many different html templates that we use, and I can reproduce the error in all of them.