MSD 2 step issue

[John Nechiporchik]

I am running an MSD Digital 7 box and a FAST XFI 2.0 system in my Firebird.
The MSD is only being used for firing the coil and the 2 step.
I have the 2 step switch on the brake pedal and utilize an ON/OFF toggle switch to activate it on the starting line. I then flip the switch to OFF when I make the 1/2 shift.
Sunday, the two step activated during the burnout when the toggle switch was in the OFF position. The two step went to 3500 RPM which is where it was set. As this happened once before, I had the MSD dial switch connected in the car and was able to set the 2 step to 8000 to essentially de-activate it. I was able to save the run by leaving on the footbrake w/o the 2 step.
After the first occurrence earlier this year, I re-wired the circuit and installed new switches (toggle and pedal).
Anyone have a similar experience? How could the 2 step circuit be activated w/o power to the switch?
Also, the 2 step stays active when no pressure applied to the brake pedal.
Any help is appreciated.
Thanks,
John