Always getting method error

I'm trying to understand if my server json works, but when I try to use curl to check the methods I always get this error:

{ "#error": true, "#data": "Invalid method " }

This is what I used:
curl --data method=system.connect http://mysite.com/mydrupalfolder/services/json

Just to give you more information: my installation is not in the root of my site and I have clean URL's enabled.

Any idea?
Thank you in advance.