My attempts give me the following message.

?Dreamweaver could not connect to the remote server. You cannot perform
Contribute administration tasks without a connection to a remote server.
Please fix the remote connection before continuing.?

All other indications in DW shows the remote server operating properly.
What gives???

I have the site definition set up and have been working on the site.  I also
have administration set up and have been testing things out in Contribute.  
I
came back to DW to create some new connection keys and modify one of them bu
t
was surprised to encounter the above quoted message.

My mistake

I added a file name to the "Site Root URL" field found in the 'Contribute'
dialog box of the site definition.
ooops
Removing that file name at the end of the site address corrected the problem
.