joomla/joomla-cms — pull request #3502 by julienV (2014-04-25 09:21:10+00:00)
Title: Fix autoloader for joomla 2.5.x

Basically, if there is a library prefix 'R' and another 'Red', it will try to find classes from Red library in R library, and fail, so the Red classes will never be autoloaded.
this is something that is fixed in 3.x version