Trying to export feature class to shapefile...missing fields

I have created database with a feature class "Regions" and imported in multiple .shp file polygons into it for various different regions, all with the same attributes. I would now like to export that feature class as one large .shp file. When I do this, not all of the fields are included in the resulting .shp file export that are included in the feature class. All of the polygon features are incldued, but all of the attributes are not.

Any ideas? I also noticed that I was having trouble doing any calulations to many of the fields in the feature class prior to exporting as well...and it would not allow any joins.

Not sure if I set something up wrong in the feature class prior to importing data into it, or if I'm missing something....Any help would be much appreciated!

Thanks
Bryan