Apache configuration files all appear correct; I've added the ExecCGI to the RootDirectory, although this file resides in the ScriptAlias directory so that shouldn't even be necessary. I put a .htaccess file out there which is also probably not necessary.
This is a simple counter.cgi file - runs fine from the linux command line; runs fine called as a "method post" from an html file. When I call it using "!exec cgi" it's as if it never happened - it's completely ignored. There are no errors in any log files - the file is not executed.