While everyone's jumping straight on the intake as the issue, I'm not so easily convinced. I drove through some awfully heavy rain (Michigan) with my iceman on w/o fender liners in, no problems whatsoever.

The two keys that I noticed are that the car was "jittery" and that it had also happened during a "small drizzle"


I think it's far more likely that you have some loose or bad electrical connections somewhere that are getting a little wet and not liking it. You'll find out for sure next time it rains and you have only the SRI section of your intake on.