InsertHTML method is duplicating inserted txt

Hello:
I have an error with the explorer.
When I load the editor for the first time in explorer works perfectly, but when I refresh the page and insert something with the "insertHtml" duplicates
CKEDITOR.instances['textmodelo'].insertHtml ("Hola");
result -> HolaHola

I tried CKEDITOR.instances[textmodelo].destroy(); but not working.

What can I do to avoid this problem?

Thanks in advance for your help

Sorry for my english