If you want a newer package to install on Debian stable, then you can always build it from the source package in either testing or unstable and port that to stable (I'm assuming you're using Debian stable). The process is described here
, with additional information about porting from testing or unstable here
(to get the newer version in a package form for your current stable release of Debian.) Also note that the sid source does contain the newest version (2.2.6), so sid (unstable) is what you would want to use rather than testing (but again, ported from source, not directly installed).