Lot/Date Code question

This is not a technical/engineering question...

I received a batch of Stratix III's of which I have two date codes (1049/1043), however both share the same Lot Code (top line of the two etched markings on the bottom of the device). I have never run into this situation before in my three years of dealing with Altera devices. Should I be concerned that these may be counterfeit/remarked, or has anyone seen this circumstance on authentic parts?

Thanks to anyone who can help!