Please could you open up Dreamweaver, and select one of your 'working' sites in your files panel.
Then Go to Dreamweaver Menu > Site > Manage Sites (selct one of your working sites) > click Edit , and copy the path of the 'Local root folder' to a text doc.
Next go to 'Testing Server' and make a not of the 'Server Model', 'Access', 'Testing server folder'. and 'URL prefix'. and copy this info to the text file.
Then could you please do the same for your 'not working' site, and then post back with the text file attached?
(Or send screen shots of the 'manage Sites' window x 4)