its steppy because of the variations in the dmx rate from the console...

in my experience lighting consoles have trouble outputting the dmx frame more than 20 times per second. especially hogs.
On hog3's its maximum is around 20
On hog 2 its less and its much more variable.

If you program a preset cue within catalyst 3.3 the intensity will be smooth.

I might move this thread to the support questions thread.

Richard