said by dynodb
:The glich doesn't happen any time a ADSL circuit is in the same count as an ADSL2+ circuit. In fact, ADSL and ADSL2+ are deployed from the same DSLAM- if that were true, none of the ADSL out of a DSLAM offering ADSL2+ would work very well.
It apparently occurs in a specific circumstance- when a longer ADSL line from the CO is in the same count as a shorter ADSL2+ one.
Good point. It can occur when any xDSL signal out of a CO is in the same distribution bundle as any xDSL signal out of a Cabinet/Node/SAC/JWI/Roadbox.