I have a similar issue.

Everything within the private network is functioning normally, but mysqueezebox.com insists that I do not have any active players, as does the android squeezebox application.

If I provide an incorrect password for mysqueezebox.com account in the media server settings, it reports a bad password, and reports nothing when given the correct password.

Let me know if I can provide any more information to help get this sorted out!

Code:
Logitech Media Server Version: 7.7.2 - r33893 @ Wed Mar 14 06:31:06 MDT 2012
Hostname: crudora.schiznet
Server IP Address: 10.20.30.6
Server HTTP Port Number: 9000
Operating system: Red Hat - EN - utf8
Platform Architecture: x86_64-linux
Perl Version: 5.14.2 - x86_64-linux-thread-multi
Database Version: DBD::SQLite 1.34_01 (sqlite 3.7.7.1)
Total Players Recognized: 2