Ty has been doing sooo much better since we took him off the singulair that it is very clear now that that was the cause of his mood problems last week.  He has done a 180 degree switch in mood.  He is happy, chipper and playful again!  We have been using the NasalCrom as well, and I think it might be helping, because we played outside a lot today, even though the pollen counts were pretty high, and he did fine!  whew!