Here's another idea to get them to bite. How about a small soft-hackle. Though the gills were working the surface on your pond, they may also be taking flies just under the surface. An unweighted soft-hackle might be interesting. A peacock body SH might be a good place to start.

That being said, my favorite panfish fly for surface fishing is a small popper, like the gurgle-pop popper shown in the FOTW archives. Not exactly a "dry fly", however.

http://www.fishingwithflies.com/Pete...PopPopper.html