Pressing return after a <select> creates duplicate

I use the template-plugin to load a form in to the ckeditor. When I place the cursor after a select-item (dropdown) and press return, to create a simple paragraph after the <select>, the entire select-element is duplicated.

Example, before the duplication: 

<form enctype="text/plain" id="dynForm1" method="post" name="dynForm1"><span style="line-height: 20.7999992370605px;">Select company:&nbsp;</span><select class="jsFillCompany" id="selCompany" name="selCompany" size="1"><option value="2">Execute</option></select></form>

Example after I've placed the cursor after the <select>-list and pressed "return":

<form enctype="text/plain" id="dynForm1" method="post" name="dynForm1"><span style="line-height: 20.7999992370605px;">Select company:&nbsp;</span><select class="jsFillCompany" id="selCompany" name="selCompany" size="1"><option value="2">Execute</option></select>

<p><select class="jsFillCompany" name="selCompany" size="1"></select></p>

</form>

Any ideas why this is happening, and/or is there anything I can try to remedy this (force save/update of the editor-instance or similar)?