I have loaded dozens of different types of film in my Pentax 645 120 insert without any trouble, but today I wrestled with loading Ilford FP4 for some time before geting it loaded. I thought maybe the film spool was a bit thicker on the O.D., so ended up spooling out too much, probably lost the first shot or two. I remember having trouble also a while back with some Ilford Pan F. Haven't run into this with Fuji and Kodak films. Just wondering if there is a difference in the spools, maybe the engagement slot is narrower? Anyone else run into this before?