Neptune
When Neptune was discovered, the French and the British could not agree on who would get credit for the discovery. Later, an international agreement decided that both Le Verrier and Adams deserved credit. However, historians reviewed the topic after the rediscovery in 1998 of the "Neptune papers" (historical documents from the Royal Greenwich Observatory). It had seemingly been stolen by astronomer Olin Eggen for nearly three decades. It was only found again (in his ownership) shortly after his death. After looking at the documents, some historians now think that Adams does not deserve equal credit with Le Verrier.