If you have set the stylesheet href as relative path eg. /example.com/wp-content/... it will append it to the current location http://example.com in your browser, so for just a relative path use just /wp-content/.
But if you specify an absolute path eg. http://example.com/wp-content/... or even //example.com/wp-content/ it will just look for that directly. Either way should hopefully bypass the problem you are having.