Asphyx, I had the exact same issue with what appears to be the same setup filter ect...tell us what temp the oil was when it was dumped into the funnel(top of the stericup) and what hg of vacuum you had on the cup.
Exact temp Im not sure, that was what I thought also, that it has melt something in the filter? Usually I keep i very WARM but not hot.. Also last time I tried to make 200 prop i came out clear as sky but crashed.
I have the pump around 20 but what the digits represent Im not too sure of