What's up with the MetroRail sounding its horn lately?

From CapMetro's Metrorail Safety FAQs:

Will the train blow its horn in my neighborhood?
Federal law requires trains to sound horns at crossings unless a quiet zone is established. A quiet zone is an FRA-approved section of track where trains are not required to sound horns at crossings. Quiet zones are established after the installation of quad gates, which prevent vehicles from driving around railroad crossings. Quiet Zones are in effect in Leander, Cedar Park and in Austin from U.S. Hwy 183 to Downtown and between McNeil/Merriltown Road and Gracy Farms Road. Capital Metro freight and passenger trains will still sound horns in emergency situations such as when there is a car or pedestrian on the tracks. Trains also are still required to sound horns when accelerating from a stopped position.

More info from the listserv:

Marshal Garland on Grover has reported that the crossings are currently malfunctioning and the trains are required to blow their horns until they are fixed. CapMetro's contractor, Veolia, is currently working to fix the crossings, but no estimates have been provided on when the repairs will be completed (Veolia’s Director of Rail Operations, Patrick Brouard at 852-7290 or patrick.brouard@veoliatransportation.com).