Drush download fails

Drush fails downloading berry.

drush dl berry
Source directory /tmp/drush_tmp_1299352966/berry is not readable or does not exist. [error]

unless you use a capital B

drush dl Berry [SUCCESS]

I think Drupal's coding standards use lower-case for theme names. Certainly that has been my experience with other modules / themes.

https://drupal.org/node/360052