Transcribe documents exactly as they read--even if they are inconsistent with other items or records. Your genealogical software package should allow you to record alternate dates of events tied to the actual source from which the information was obtained. Never change what any sources say. In your notes about the person, comment on the differences and why which one of them (if any) you think is more likely to be correct.
Some discrepancies can never be "explained away" and one cannot expect all records to completely agree.