The version numbers of gnats 3.x is somewhat confusing, because 3.1xx is newer than 3.2.
Version 3.2 was released in 1993 (I never tried it, but it is said to be "really broken"). A lot of new features have been added since 3.2, including multiple database support and customized fields. Among the contributed software are comprehensive WWW and Tk based front-ends.
The latest 3.x release is 3.113.1.
A first beta of version 4.0 is available since January 10, 2002 (as ftp://ftp.gnu.org/gnu/gnats/gnats-3.999.1.tar.gz), and an official release is expected very soon now.