Slight in error in git-rerere help page

Hi, people.  This is for git version 1.6.4.rc3.12.gdf73a

The output of "git help rerere" contains:

   You need to set the configuration variable rerere.enabled to enable
   this command.

It seems that that "enable" is not a proper value. If I used it over a small repository, I get:

   22:17:33 0 pinard@phenix:etc $ git config rerere.enabled enable
   22:17:44 0 pinard@phenix:etc $ git gc
   Counting objects: 1072, done.
   Compressing objects: 100% (559/559), done.
   Writing objects: 100% (1072/1072), done.
   Total 1072 (delta 460), reused 1072 (delta 460)
   fatal: bad config value for 'rerere.enabled' in .git/config
   error: failed to run rerere

Removing the rerere section repairs this last problem.

P.S. - I'm also a bit curious about why rerere is needed for a garbage collection.