This happened to me. Did you stir the sugar well? In retrospect, that was my issue. Good news, it finally carbonated after about 60 days, but not all that well.
Is the air coming rom the post or from the connection between the tubing and the connector? Without being there:
1.) use a hose clamp (i didn't always, but had hissing also)
2.) look for significant dents on your IN post
3.) lubricate all rubber with sanitary lubricant.
keep on brewing!
I have been experiencing the same problem with an american pale ale. The only difference is that I'm 3/4 of the way through the keg and it's still cloudy. This is half of a 10 gal. batch and the other half was nice and clear. So many variables...