I am pretty sure this is CSS issue but I can't find it.

I have 2 ways to access my site - running locally in VS2010 and also via the browser accessing my staging server. The staging server runs my last build and both access the same database so all control settings and content are the same.

The problem - after doing some CSS editing and refactoring in VS2010 when I view a blog post entry following the blog title link locally with my edited CSS the entire left column disappears and the content layout looks like this

<div class="art-content-layout-row">
<div id="ctl00_divCenter" class="art-layout-cell art-content-wide center-nomargins cmszone">
<a id="startcontent"></a>                       
<div id='ctl00_mainContent_pnlOuterWrap' class='art-post'>

Whereas viewed via the site running on the staging server we get as expected

<div class="art-content-layout-row">
<div id="ctl00_divLeft" class="art-layout-cell art-sidebar1 leftside left2column cmszone">
<div id="ctl00_PageMenu1_upMenu">
<div class="art-vmenublock" id="ctl00_PageMenu1_ctl01">

.... all the menu 

</div>
<div id="ctl00_divCenter" class="art-layout-cell art-content center-leftmargin cmszone">                        <a id="startcontent"></a>
<div id='ctl00_mainContent_pnlOuterWrap' class='art-post'>

I could revert to the published copy and start over but I have done a lot of work on the CSS on the local copy so I would prefer to fix it.

Everything else on the site displays as it should just blog posts are losing the sidebar on my local tweaked copy.

Any clues?

J