What they are saying is correct, but implementation could be tricky given your set up.
Given the following two urls, the first will always rank better, as it contains keywords that you might be trying to get ranked for.
http://humana.org/Teacher Training.aspx
http://humana.org/TextPage.asp?MenuItemID=42&SubMenuItemID=144If you were attempting to get ranked for the keywords "teacher training", the second url would fail miserably. Some search engines won't even index your site if you are using querystring parameters as you are.
both the URL and the text of the link are important.
You might look into doing some URL rewriting to provide nicer more seo friendly URLs