CGI error in civicontribute?

[tcporg]

Just installed CiviCRM and everything is working great, except when testing our contribution form. The form is located at http://thecommunityproject.org/get-involved/donate/

When the form is submitted the address in the url looks like this:
http://thecommunityproject.orgcgi-bin/webscr?business=i...

It looks like the problem is right after the site url where there is no slash, but I cannot figure out how to fix this issue. I have checked all of the configuration files, and all of the base urls have the trailing slash.

Thanks for your help!