I have created a site in DW and our client administers it in Contribute. All was well until we replaced the index.htm file with a index.php file. Now each time he connectes Contribute looks for the index.htm and reports a 404 error. We can then navigate to the index.php and start editing, but is there a way of removing the reference to the .htm file so that Contribute goes staright to the .php file.
Try this ...
Go to Edit --> Administer Websites --> select your website
Then select the role of the user and click on "Edit Role Settings". Under the General options, change the value to index.php for "Home page for users in this role".
Now Contribute should go to index.php instead of index.htm
I hope that helps.