Hi

I am hoping someone can help me with this. I am wondering if it is a difference in perspective with the sentence, a difference between American and British usage or just my lack of knowledge!!!
The sentence:
Some think the pyramids were built by slaves, but this has been proven to be wrong.
Some think the pyramids were built by slaves, but this has been proved to have been wrong.
The second sentence feels strange to me, but I can not explain why. I also don't feel comfortable with using two 'been' and 'been' in the same sentence.
Can anyone tell me which is correct and why?
Thank you in advance.
riceball!