animal movement extension in arcview

Hello,
I'm using the animal movement extension on ArcView 3.2 and have been trying to calculate MCP area sizes (in sq-km).
Everything looks fine with the MCP shape file, however, when I try to calculate the actual size of the polygon (the MCP) I'm getting some unrealistic numbers.
I'm using the 'animal movement extesion' to create the MCP and I'm using the 'Xtools extension' to calculate the area.
my view projection is set to tranverse mercator, WGS84
and map measurements are in meters
the xtools defauls are in meters and hectare

If anyone can see any faults in these settings that might create some unrealistic measurements please let me know.

Thanks,
Daphna