Nope, apart from the odd bit of shoving and grunting at each other when they all try to fit under the same piece of bogwood at water change time all my cats get along peacefully.
However this is not the rule for all catfish, the majority of my cats are from the Pimelodidae family which are not known to be aggressive but some catfish, particually those from the Bagridae and Siluridae families, are truely evil terrors that should never be kept with any other living creature.
I dont have room for aggressive fish as the value of my stock is just too high to risk any damage being done, at the first sign of a new fish showing aggression it is netted bagged and heading for the LFS without a second chance.