I'm having a hard time finding literature on problems like this. I think the closest thing it's like is the stable matching problem, but I'm not sure. My current algorithm doesn't allow for missing or reordered pages.
Does anyone have magic words I could google to find pertinent research/algorithms? I think if worst comes to worse I'll have to try to model the incoming page stream as something like a bayseian ... graph? It's been so long since I've done something like that (5 years), and that was in school.