A google image search for epinasty shows some very interesting things. Pine tree spring growth showing (epinasty) twisting and curling new growth caused by an auxin herbicide. Tomato plants showing twisted, curling from pollution or herbicide use. Ethylene gas makes this happen, also. And, I believe, some viruses.
Hum. Yes, I'll have some photos by Friday afternoon, I know of a few papaya plants that are virused, and the leaves exhibit this growth 'malfunction'.
