Well, your getting that error because when the install script try to test the following url, it's getting a 502:

http://www.motoplexspeedway.com/cms/index.php/install/-/test_url/20...

That said, its not just C5 that is having trouble with these type of urls... for some reason your install of fastcgi/IIS6 seems to be having problems with all of them... for example, this url should just "work":

http://www.motoplexspeedway.com/cms/phpinfo.php/testurl/ok...

but it doesn't...

To be honest, the entire config looks like it should be working, so I'm not sure what your host has installed that is breaking pathinfo style permalinks... I would recommend contacting your webhost and seeing if maybe there is a configuration setting on their end they can update to make pathinfo urls work properly in IIS.

Hello, I am having the same PATH_INFO issue, but when I try the test_url it does work and returns a value. Site:www.www.coolspringsgroup.com/index.php... and phpinfo atwww.www.coolspringsgroup.com/test.php...

thank you in advance for any help.