did you ever figure the problem out with displaying xt data from an Access table and the data not displaying? A colleague had the same problem today. He had records in an Access table, had valid easting/northings and whenever he did the Display XY, he never got an event theme.
We created a geodatabase, imported the Access table, and tried that but it still wouldn't work. Yet, I was able to Display xy from the same geodatabase on my workstation.