an integers max value is around 2 billion, So i can see why this isnt working, maybe the int is signed to 16 bytes, 32, or i wouldnt think 64 because a 64 byte long int would be declared as a long, and can take up to trillions i presume, Your points are at a max value, overflowing to 0 (or any other number, i don't know how as3 stores its variables), Its a simple bug to fix if you replace the signed amount... robby.
Backing up my claims:
https://msdn.microsoft.com/en-us/library/296az74e.aspx