Install Roadblock! "Referring Page link outdated/wrong" message

Hi All.

Have configured my server & was pleased to see the Elgg Install page appear in my browser!  :-)  However, upon completion of the fields on the install page & clicking Save, I'm presented with the error below.  Appreciate any advice that can be given.  

Thanks, Eoin

Object not found!

The requested URL was not found on this server. The link on the referring page seems to be wrong or outdated. Please inform the author of that page about the error.

If you think this is a server error, please contact the webmaster.

Error 404

Tue Jun 8 15:33:01 2010
Apache/2.2.14 (Unix) PHP/5.3.1