Yahoo Transport sending badly formed error message?


The following is an error message I received from Yahoo gateway from IM Gateway plugin version 1.2.4d running on Openfire version 3.6.3:

Login refused by Yahoo!, perhaps because of a bad password. Please re-register with correct password.

This is causing an error in my XIFF library, which is looking for an child inside the message. According to the RFC:

9.3.1.  Rules    The following rules apply to stanza-related errors:    o  The receiving or processing entity that detects an error condition
      in relation to a stanza MUST return to the sending entity a stanza
      of the same kind (message, presence, or IQ), whose 'type'
      attribute is set to a value of "error" (such a stanza is called an
      "error stanza" herein).    o  The entity that generates an error stanza SHOULD include the
      original XML sent so that the sender can inspect and, if
      necessary, correct the XML before attempting to resend. **   o  An error stanza MUST contain an <error/> child element.**    o  An <error/> child MUST NOT be included if the 'type' attribute has
      a value other than "error" (or if there is no 'type' attribute).

Is this a bug in the Yahoo gateway? Please let me know, all help will be appreciated.