Also the throttle hang fix tends to reduce this.
It is inherent in the SVT. To me it feels like the idle air control is working against the idle. The speculation is that the SVT is more prone to this because of the hotter cams (slightly less low end torque) as well as a lighter flywheel.
On my car it is most pronounced when running the A/C and trying to hold a steady speed in 5th gear at about 35 to 40 mph.
Having the engine in good tune (plugs and wires in good condition), the throttle body clean, the IAC clean, and the injectors clean seem to help some, and then the throttle hang fix seems to remove even more of it.
