Problem spawing The Snow Queen in Pagos

[OlafQuintessa]

Heyo.. I am at a loss as to why the first NM of Eureka Pagos won't spawn (The Snow Queen from killing lv25 Yukinkos).. Went through soooo many chains of them and gave up. Moved on to the others (Ash Dragon, Taxim, Glavoid, Hakutaku) and they all spawned in three chains or less. Went back and did more Yukinkos and nothing. The instance is empty apart from me and I'm pretty sure it was a new instance when I entered (I am on Materia and it was 8.30am in NZ!). Have tried in snow and at night. The online guides don't mention any specific requirements. I am level 34. Am just stuck with it. Anyone have any ideas?