Perhaps the gasket wasn't seated correctly initially, but has now seated itself.

*EDIT: my long windedness allowed someone else to chime in first! Steve and I are thinking the same thing.*

Paul, I'll offer my hypothesis which may also explain the leaking when the pf isn't really cranked. Sometimes those group gaskets can fit pretty snugly in their groove. I think maybe the gasket was installed but was so snug that the assembly person didn't notice that it wasn't seated all the way. I have done this myself and wondered if I got the wrong gasket until I realized it wasn't all the way in. So my guess is that at some point, the gasket seated itself and now is installed properly, allowing the pf to be inserted as it should. So now is the leaking gone? You shouldn't have to really crank it to keep it from leaking on a new gasket, so something must have not been sitting right.

Used the machine once, it didn't leak. I can't believe how much easier it is now to insert the PF. Doesn't take any effort at all, and the gasket felt smooth, whereas before I had to crank it so hard it felt like I could be twisting the machine.