It depends upon what exactly is going on with those points.
If they were banked from 2005 to 2006, yes, they will have to be used by March 31, 2007, or lost.
If they are 2006 points, you still have a banking window, and could bank them (depending upon the total size of your contract and any previous banking) in to the April 2007 use year.
Or, have they already been banked FROM 2006 to 2007, in which case they need to be used between Apr 1, 2007 and March 31, 2008.