I had the same problem. To get around it either try using the original version of admin.cgi and JUST change the path to your links.cfg file if required.
If this does not work, try changing
/admin/admin.cgi
to:
/full/path/to/admin.cgi
Then the next thing you can so is to check permissions as 755 (rwxr-xr-x). Also ensure you don't need to have your cgi files in a certain directory to execute on your server.
Lastly, look in links.cfg and check the first few lines point to the right places/
Hope this helps! I just added the original version to my site, and it worked again!
Ben
------------------
-------------------------
http:/www.t-e.co.uk