Try bending the leg of the wire form a bit so it's embedded in the lead better. I've had to play around with making some of my own wire eyes for those smaller sizes. I haven't lost any blades but the wire eyes would get loose.
I use a hard lead, wheel weights, and as long as I keep the mold hot don't have any problem pouring, but don't think those wire eyes work as well as they should in some of the cavities.
I have the same issue with the freestyle molds, and that wire keeper, they get loose too easily. So, I started using the longer wires, and make sure the bend in the wire is at 90 degree's so it stays in the lead.