As ABC News is replayed multiple times throughout each day via the ABC News channel on channel 24 you may want to only record the ABC News showing at 7pm on channel 20 (ABC HD) instead of many times each day on the ABC News 24 channel.
To do this when setting up the series recording from the IceTV website or IceTV phone app you leave the Advanced Option set to "Prefer High Def.". This will ignore any of the showings on ABC News 24 (as channel 24 is broadcast in SD) and will only record ABC News on the main ABC HD channel (on 20). Now click on Advanced Options and set the 'This Time' option to 7:00 pm which will then record the ABC News on channel 20 but only for showings that the guide has listed to start at 7pm.