alixdsgn

That is a good idea. I am gonna try right now.
Another way I found is to add an extra empty div with the correct span according with the bootstrap grid.
For instance, a full width page with sidebar is by default:
<div=.. class=”span8″ (primary content)><div=.. class=”span4″ (secondary content)>
If I want a narrow centered content it will become:
<div=.. class=”span1″ (empty space one the left)>
<div=.. class=”span6″ (primary content)>
class=”span4″ (secondary content)>
don’t need to set another div span1 cause the elements are floating left

Appearance > Editor > Stylesheet (style.css)

I changed the top margin in here:

#wrap {
	max-width: 960px;
	margin: 20px auto 0 auto;
	padding: 0px 30px 0px 30px;
	z-index: 0;
}

#wrap {
	max-width: 960px;
	margin: 0px auto 0 auto;
	padding: 0px 30px 0px 30px;
	z-index: 0;
}

Ok I know I am not a CSS genius but hopefully this topic will help someone with the same issue.

??

Ohhhh I did it!

From this:

#sidebar-primary {
	width:240px;
	margin:0px 0px 60px 0px;
	float:left;
	position: fixed;
}

To this:

#sidebar-primary {
	width:240px;
	height:100%;
	margin:0px 0px 60px 0px;
	float:left;
	position: fixed;
	overflow: auto;
}

Now the only problem are margins.