Ian, I completely agree with your view that it has been a strange year so far moth-wise.  It seems to me to be entirely down to the generally low night time temperatures.  For example last night, July 3, it was down to 8 degrees and I had only 15 species in the garden trap with only one first for 2008 a Scalloped Oak while on July 2nd when 12 degrees was the lowest and I had 40 species including the first Buff Arches and the first second brood Early Thorn.