geradus,
Well of course the i-node is updated when anything references the file - so the time last accessed is the time the file was last accessed, hence the name....as your backup reads the file everynight there is no way to find out when it was last executed. If you had not backed up the file then the time last accessed would be when it was last executed if the updated and modified time were not updated at the same time.
Cheers
PSD
IBM Certified Specialist - AIX V4.3 Systems Support
IBM Certified Specialist - AIX V4 HACMP