Dewpoint - from recall memory of studying the act (for IT GCSE in 2000), this is not a valid excuse.
The DPA is there to protect your information being held:
- correctly
- in safe/secure manner
- not given out to people to whom should not have access
Giving you reasons about your job should be given to you unless the data contains personal information about someone else (highly unlikely, from what you have said).
Jordan