Set yourself up with a no-ip.com address, or a DynDNS address (I think DynDNS charges, but no-ip is free), and use that as your server address instead of the *.subsonic.org address on your mobile device.
NAT loopback is different than DNS forwarding and port forwarding.
There's an issue with the DNS servers that Subsonic uses for the *.subsonic.org domain forwarders; the only fix would affect all of the other clients that the DNS provider has (assuming the subsonic.org domain is not their only client), so that is why they aren't fixing it.
The workaround I have found is just to go with no-ip.com or DynDNS.
If you can manually edit your router's DNS settings then you can make this work. And you can even on a simple FIOS MI-424wr router.
If you have DynDNS - let's say you're using a free version of noip, and your address is myaddress.hopto.org. Add a manual entry in your router's DNS table that points myaddress.hopto.org to your madsonic server's internal IP. When you're on the LAN, voila - your router sends you directly to the server, no need for NAT loopback. And when you're outside the LAN, your phone uses public DNS servers and is sent to your server's WAN IP.
on server a drop a few new MP3s into one of the music directories. Then, in the middle of the night Madsonic server is set to rescan every night... so next day, on android client, i select New Added, and i do NOT see the newly added tracks.
What's the problem??
What's the point of New Added if it's showing me some very old stuff, and NOT showing the new files i added??