I still don't get why people are all about the Sylvans. If you want a low-dollar pedal for clips, it seems like the GR9 is a better, more supportive pedal for a lot of people. I'm running generic pedals similar to the Wellgo track pedals and they're great. Super comfy and none of the digging action of the Sylvans.

That said, if you're having this problem, you might look into some stiffer insoles like you can get at decent outdoor stores. Also consider stiffness of the shoe sole as a primary factor. FWIW, I've found my Onitsuka Tiger's to be essentially perfect for clips and straps. Just stiff enough, just padded enough.