I ended up having to delete the Geometric Network I had created w/in the Water Distribution Feature Dataset (in the SDE) in order for my crews to be able to once again view and utilize all the feature classes w/in that dataset. Once I deleted the Geometric Network - access was back to normal for all users.
You've hit the nail on the head as to why I avoid feature datasets and the data there in while in the SDE environment...
That should just about do it....