Steve, sometimes on roses that are having trouble leafing out you have to sweat the buds out. Put a large clear plastic bag over the canes, then punch a couple of small holes to let some of the heat out, but hold a lot of the moisture in. This will help as we call it, sweat out the buds, Once the leaves are growing out nicely, you can take the bag off. Not sure what your high temps are, but if your still in the 80's should be fine with just a couple of holes in the top of the bag to let heat escape.
Alan
