cruise control Super Sensitive

1998 b2500, yes its a Mazda, at least it says so on the tail gate, but everything on this pickup is stamped FORD. looks just like a ranger! beside that, I couldn't find pickups in the Mazda forum!
The cruise control is a stem off of the steering column with a push switch on the end and a slide switch on the shaft.
Once the cruise control is set, it will hold the speed but it dose it in such a precise way, that it accelerates or slows with much less than 1 MPH change in speed.maybe as little as 1/4 MPH. It is sooo annoying to have it feel like some one is pressing on the gas or resealing it every few seconds.
Is there a way to make it not so sensitive as to constantly overshoot and under shoot the set speed.
Has anyone previously had this problem?
How does this cruise control work? with a cable or with electronics?
Thanks in advance for your expertise and experience that I'm lacking.
RC

Additional information;
While pulling a small pop-up trailer with a partially loaded pickup, the cruse control on level ground worked better, not perfect but much better than with an empty pickup.
The pickup has a small 4 cylinder engine, 2.5 I believe, therefor the cruse didn't work well going up hills.