Long URLs

Why google is not indexing again lon URLs after first indexing?

[dbansal]

I got a site with URLs like

http://www.WWW.com/productlist.asp?CategoryID=C001&mini=&letter=D

Now these are like static URLs as the are permanently linked with text and donot change.

Site was started 8 months back and after that it is not updating these URLs!

The page shows grey bar in google toolbar + no cache in google BUT it is still showing url in site: command.

What should I do resolve this? I am not getting keyword density because of this as most of the pages are like above...