Sleep for everyone? Not according to Avery!

Some days my son just does NOT want to sleep. Take for instance monday...he would not take a nap all day (and we were having pictures taken that evening of all days!). Then when putting him to bed that night I thought for sure he would go right to sleep. But NO, he cried for at least an hour and a half before finally falling asleep. He wasn't really fussy during the day, he just WOULD NOT take a nap. The next day however he napped just fine but still had trouble falling asleep at night, and woke up twice. He is just inconsistent and hard to figure out :) We usually try to shoot for 3 naps about 45mins-1hr long each day, but every day is differnt. We have tried the whole schedule thing and he just refuses to adhere to it (or is that mommy who sometimes loses track of the schedule...hmmm). I will say though that when Zac keeps him on Fridays while I go to work he usually sleeps like a jewl...wonder what his trick is!?!