Hey,
This is a joomla issue i think. This can be solved by changing the text: "Your password reset request failed because a User with the specified username and e-mail address could not be found.." You can find this text in the joomla language file for the user component of joomla.
But it is no error. Its just a standard phrase there using there. I dont know why either
I just provided the link to it. You can discuss it it the joomla forum:
http://forum.joomla.org/
Kim