dreamweaver pages loading slow

Hi! I'm having a problem with my new dreamweaver sites loading
extremely slowly. I have inserted a fireworks navigation in the
template for the site ... when I check the download time of the pages
it is 50k or less ... any ideas why it would be so slow? Could it
have anything to do with our firewall?
One of the sites that is too slow is: http://www.mtregis.com

Any ideas? Thanks!
Kathy