Proximity Alert Distances

I don't know about other brands or models but I have a new (2 weeks) zumo 660 that I have setup 2 different POI files with proximity alerts. Used POILoader in manual mode.

The Rest Stop Combined POIs work fine but the Harley Davidson Dealers doesn't work on the few stores I've driven by.

The difference, I guess, is that the rest stop POIs are directly on the road I am traveling on while the H-D POIs are just to the side of the road traveled.

I drove by a dealer today and found I had to actually pull into the parking lot for it to alert me, instead of 1 mile before. I did this twice, once while driving past the store on a calculated route to a destination a few miles further down the road and a second time just driving by the store.

It just seems a little quirky. I am only guessing then that any POI file that doesn't have its coordinates directly on the road being traveled will never work with alerts.

Not quite sure how speed alerts work but my last GPS, an early iFinder (yeap, the screen died, all 4 grey colors), would sound a proximity alert anytime you came with in the alert distance as a crow flies, no matter where it was from the road.

So is it that quirky or am I doing something wrong?