Over 60% of my pages do not get listed

[bob20]

Over 60% of my pages do not get listed.
Have over 450 pages on my site (ShortOrderProducts.com).
Purchased your unlimited listings with extras (including your installation).
When generating an XML sitemap, it only lists 155 pages while the HTML sitemap lists 164 pages.
What could be wrong here ?

[XML-Sitemaps Support]

Hello,

replied to your email.