Update 2015-05-04: 1.3.7 is gone from the repository, and locations have changed depending on sid or jessie in use, please see this post for Version 1.4.0.
Recently Plex Plex Home Theater was updated to 1.3.7 fixing a list of bug. So here is now the Debian/jessie and sid builds, as usual for amd64 and i386.
Add the following lines to your sources.list:
deb http://www.preining.info/debian/ sid pht deb-src http://www.preining.info/debian/ sid pht
The release file and changes file are signed with my official Debian key 0x860CDC13.