wp removes code

my problem is this: i’m using the “lifestyle” theme from studiopress and when i try to insert a div tag to stop the blue header background from appearing behind images in the post, wp removes the div code. here’s an example:

http://bestbabyshops.com/wordpress/?p=1406

studiopress told me to modify the img code by adding this div tag (and it worked, but then wp takes it away):

<p><img class=”alignleft size-full wp-image-1446″ src=”http://bestbabyshops.com/wordpress/wp-content/uploads/2009/03/whitespace600x10.jpg&#8221; width=”600″ height=”10″ /></p><div style=”clear: both;”></div>

i’ve been reading sold pretty old posts about how wp automatically removes certain code if you use the wsy-thing and then try to put a line or two of your own code in the html editor.

it seems that the “text control” plugin could address the issue, but it hasn’t been updated since 2005, and i read that it doesn’t work with the newer versions of wp.

so i’m wondering if there is a solution to this problem or should i just create a new page in the html editor and try coding it myself?

any ideas would be appreciated 🙂