http://www.immigration.com/newsletter1/newac21guidance.pdf#search=%22Yates%20Memo%20AC21%22
Question 14: Must the alian have a new offer of employment at the time the I-485 is being adjudicated under the I-140 portability provision?
Answer: Yes. The alien cannot still be looking for "same or similiar" employment at the time the I-485 is being adjudicated under the adjustment portability provisions. The alien must be able to show there is a new valid offer of employment at the time the I-485 is adjudicated.
Although it says so, I think you have have different real cases. As this is essential to my case, I want to clarify it.
Thanks a lot!