Inconsistent Drawing for Feature Layers

Since layer themes are not currently supported, I actually created a new site with an HTML5 viewer that contained just a couple feature layers from a larger map service.

This was done in an effort to control the layers within the site/viewer because I didn't want to publish a service that just contained two layers.  The problem is that one of the feature layers just has a handful of points (5). Depending on which scale you are viewing the points, some do not draw. At the initial extent, they are all drawn, but if I zoom in a single level, a point or two will disappear until I either move the map, or zoom to another zoom level. This is not consistent for the same point/location. It's very inconsistent.  If I add the entire map service and only have the two layers displayed, it does not behave in the same manner. I see all of the points at all scale levels. It seems to be limited to the feature layer.

Does anybody have any ideas?

Thanks.