Hi, I think I have a similiar problem to these posted problems here.
The Data Frame of my ArcMap Document has the Coordinate System UTM Adindan 37N, due to the fact that the initial shapefiles of teh area were set to this Coordiante System. I wanted to add some GPS points. The GPS was set to WGS 1984. I add the GPS points as an excel file (and calculated them into Decimal Degrees) and used the button addxy data. I turned the Coordinate System of the Input Coordinates to WGS 1984. The points appear, and they are broadly in the right area, but there are not correct. They are also not shifted to one sight, but seem to be distributed totally wrong.
I made a screenshot, the green points are where the points should be located, and the brown points are the points which I got.
I hope, sombody can help me with this. Thanks in advance!