I have tried that and although it gives me some control with the CDJ in Traktor I am having problems with the software running slowly when I add effets. The track breaks up and makes it impossible to mix as I am contantly losing pace with the tracks.
That why I think I have them set up wrong, my laptop has 4g ddr ram and core2 solo processor so it should be able to cope with the program.
Are you trying to add effects the the 400s? If so, you can’t when you are in Native Support mode.
If you are talking about effecs with some other controller in MIDI mode, then there may be a latency issue.