I would think that ,dependent on the thermal ramp rate and the temperautre spike at the entrance into the solder pot, you could damage a cap if one lead enters first or if both leads enter the same way and the part/PCB hasn't ramped up properly or the thermal rate of change isn't even across the part. Do you have a profiler that you could attach a thermalcouple wire to and chart what the part is seeing during the wave process?

Kathy