I have a spread sheet with coordinates that once I bring in to Arcmap, the attributes disappear. The points are on the map, and when you Identify each point, the data shows up, but when the attribute table is open, the attribute titles are there, but no data below them. I have another table with data that comes in as it should. I was able to Display XY data and reproject, and the attributes showed up, but then there was only one point on the map (there is a total of 15). I've attached a screenshot of the excel table, but let me know what other info is needed.
Here is a very useful ESRI blog you (and anyone else) who intends to link data held in Excel with ArcMap should read. It explains the many pitfalls there are with Excel.
I personal avoid using Excel like the plague and get my data into personal geodatabase which is essentially a spatial enabled Access database. Much easier to read and write from and you have ObjectID fields.