Last modified: Friday, December 23, 2005 12:43 AM EST Simulcast bill off track An on-again, off-again attempt to extend simulcasting at Massachusetts race tracks is off again. State Rep. David Flynn, D-Bridgewater, blocked passage Thursday of a compromise bill that would have temporarily reauthorized simulcasting. As a result, race tracks across the state are once again facing a Dec. 31 deadline, after which they will close if permission to operate simulcasting is not extended.