I could not reproduce this error you encountered, i suggest you look in the xml file at this section:
<component name="ul" type="" level="0" childSelector="false">
<css>
<media type="all">
<list-style-type>none</list-style-type>
<margin-top>0</margin-top>
<margin-right>0</margin-right>
<margin-bottom>0</margin-bottom>
<margin-left>0</margin-left>
<padding-top>0</padding-top>
<padding-right>0</padding-right>
<padding-bottom>0</padding-bottom>
<padding-left>0</padding-left>
<cursor>default</cursor>
</media>
This section describes the settings of: <ul class="level-0" id="cssmw"> that can be found in your HTML file
I think it's a problem with the margins and they should be zero in your case. I looked through the code and this is the only place where the class "level-0" is described. (It's probably set dynamicly with Javascript).
I hope this helps.