Problem with my IIS5 configuration & Googlebot

Page displays when it should return 404

[Fitz4David]

I am not sure if it is a problem, but I see googlebot accessing pages that aren't pages and getting a 200 response instead of 404.

[domain.com...] works on my site and I am not sure it should. I noticed that if you do the same on microsoft.com/default.mspx/ it works too, but on my site any relative links (images, stylesheets, etc.) no longer work so I don't see any use for it.
I can't find anything in IIS settings that makes it work or not work.

I noticed that Google's count is grossly inflated when I do site:www.mydomain.com and it may be related.

I started looking into my logs and I see that googlebot is scanning with a 200 status pages like
/somepage.aspx/someotherpage.aspx

This doesn't seem good. I never see somepage.aspx/someotherpage.aspx in the google results and my somepage.aspx result is okay.

It is a hard subject to search for a solution so I thought some other webmasters would have some thoughts.