I had lots of problems keeping the soles on my boots too. Intill I started using the felts from Outdoor Emporium and cleaning the soles the best I could with sand paper. Next wiped the surface real well with acetone. But the thing that made the most difference was I washed the felts and put them in the dryer first, before puting them on the boots.
It seemed if I didn't, the felts would shrink and pull them right off the boot. Any way since I have been doing that I've had no trouble.

Remeber to tape the felts on real tight.