Originally Posted by UKtravelbear

whilst i welcome you to flyer talk I should point out that it is not a specialist immigration website - there are plenty of those found on google.

But which passport was it stamped in?

The post titles says stamped in old passport but your text says new passport

How can people advise you when you give contradictory information?

assuming it was stamped in your old passport in general it shouldn't matter as long as you take both passports with you when you travel so the airline and immigration officials can see it.