I was wondering if anyone has come across this API return message:

[message] => field integrity exception: PricebookEntryId, unknown (versions 3.0 and higher must specify pricebook entry id; others must specify product id)

 I have not seen this, but I do understand what is asking. The reason why I am posting this is because:

How are we supposed to know what the version is when we are creating an opportunity line item?

If somone could please share that with me, I will be greatful

Thanks,

~Mike