From NEWS:
Major changes in Gzip 1.3.6 (2006-11-20)
* Fix some race conditions in setting file time stamps, permissions, and owner.
* Fix some race conditions in signal handling.
* When gzip exits due to a signal, it exits with the signal's status, not 1.
* gzip now restores file time stamps to the resolution supported by the time-setting primitives of the operating system, typically 1 microsecond. Formerly it restored them only to the nearest second.
* gzip -r no longer attempts to reset the last-access times of directories it reads, as this messes up when other processes are reading the directories.
* The options --version and --help now work on all gzip-installed executables, and now use a format similar to other GNU programs.
* The manual is now distributed under the terms of the GNU Free Documentation License without invariant sections or cover texts.
* Port to current versions of Autoconf, Automake, and Gnulib.