I compared the code and the Joulecoin and Bitcoin code is exactly the same.
Try modifying the HTTPAuthorized function in file src/rpcserver.cpp at line 374 to print to the debug.log the passwords it is comparing:
Tried that with the client...looks OK. Tried with curl...why is the RPC username in one string and not the other? Let's have another look at joulecoin.conf...

Somehow I had used "rpcuser
name=salfter" instead of "rpcuser=salfter" in there.
Just fired up MinerSwitcher, and XJO is showing up alongside the other coins.
