Hi Brian,
The following schedule should work. Each pair of players meets exactly 3 times, either once as partners and twice as opponents, or twice as partners and once as opponents.
( 1 7 10) v ( 5 6 9)
( 2 8 11) v ( 6 7 10)
( 3 9 1) v ( 7 8 11)
( 4 10 2) v ( 8 9 1)
( 5 11 3) v ( 9 10 2)
( 6 1 4) v (10 11 3)
( 7 2 5) v (11 1 4)
( 8 3 6) v ( 1 2 5)
( 9 4 7) v ( 2 3 6)
(10 5 8) v ( 3 4 7)
(11 6 9) v ( 4 5 8)
Hope that helps,
Ian