Popay - it is getting a little confusing for me, as I do not know which set of FDP tables you are using.
AFAIK, using the UK tables, the best planned 2 crew FDP I can produce is 11:45 on a Level2 variation. The issue would appear to be more about dropping the second crew member, which appears to make the flight unrosterable by my book. Which set of rules is your airline using?
You also say flight time 'used to be 12:45", then you quote scheduled block time "11:45" and 'doing it in 12:12" so I am getting a bit lost. All the UK FDP tables used are available at the JAA website in the sticky at the top of the 'Tech Log' forum.