Yes, I have also heard from EVO 8 owners in USA who have the same thing happen. It is either firmware related or wiring related.
I know of a few S15's that have had no problem.
Latest firmware revision is 1.3x
Also GReddy now have released harnesses for the emanage so there is no need to splice wires.
Honda's
http://www.trust-power.com/06new/2485_e_m.html
Toyota's
http://www.trust-power.com/06new/2406_eman.html
There is one for nissans, but only for GTR's.