OT Dreamweaver and css

[Roger and Rosemary Horton]

I've just been setting up a new website (for a friend) All was going 
swimmingly, but all of a sudden whether I link the css sheet  with 
document relative or  site relative links the pages are  still not 
loading the style sheets.
At the same time, when I try to change the style sheet Dreamweaver 
loads the css sheet on the remote site.

Strange! Anyone got a clue?
Rosemary Horton