When my 2 children were very little, they were on the 3x day dosing for the Cortef.  At about age 3 and 4, also when we switched endos due to a move, we went to 2x day dosing for the Cortef.   My children are now 6 and 5, and their levels seem improving.  We were kind of out of whack for a while due to the problem with the suspension, and it has taken us about 2 years to get everything back on track.  Our particular endo prefers 2x day dosing, but I know that this varies by doctor and school of thought/treatment.  My children only take Florinef once a day.