URL rewriting for SEO

URL rewriting for SEO
Dear Friends,

Am a technical person and helicon htacces for rewriting URL for the a site made in asp.net. The site has really a very bad structure. Theres just one folder with all the files placed inside it. Am using htaccess to follow the directory structure so that the SEO purpose is solved.

Now my problem is my SEO expertise manually changes the URL and get backs to me saying that its an duplication n all blah blah...

I hardly understand SEO

Like suppose

if i have a url like
<pre>
mydomain.com/folder1/folder2/article-name.aspx
</pre>
keeping in mind there are no folders exisiting like folder1, folder2.

she edits the URL manually like
<pre>
mydomain.com/folder1/folder3/article-name.aspx
</pre>
and claims its an error. Is there any way i can fix this.
______________________________
SEO|SEO UK