@created returns the creation date of the document Carl Tyler 1.Aug.18 11:50 AM Lotus Notes Domino Designer All ReleasesAll Platforms
You don't say exactly what your inconsistency is.
Taken from Domino Designer Help
Time-date. The date when the current document was created.
@Created differs from @Now, in that @Created returns a time-date value that remains constant, while @Now returns a dynamic time-date that changes with each formula evaluation when it is used in a computed field.