My 99 SE Sport 2.5L DOHC MTX75 has done that since I bought it new. However, it is so intermittent that I haven't been able to capture it with my monitor. I've spoken with the calibration supervisor and one of his engineers for this vehicle line. IIRC, they told me that they fixed this problem in an earlier version of my PCM. I didn't have the time to follow up with them more then and since the vehicle is no longer being built, I'd probably have a hard time finding anybody who remembers the calibration well enough to help out.
I'm pretty sure that it is a software/calibration thing and we pretty much have to live with it.
