Does it exist defects in the core parsing files of amaya 7.2 and before?

Hi :
      If you trace the amya version, you will find that the core parsing
files(xmlparse.c xmlrole.c etc)are different between amaya 8.0 and the
former version such as v7.2 ,v 6.2 and so on. The latter includes hashtable.
c, while the former doesn't exist. Does it exist defects in the former core
parsing files? Who can tell me the diffrence? 
Thanks in advance.

Best regards!


                                          Chris