"A friend retired last week and was solicited by her former boss to do some parttime work. HR told her that she could not receive a W2 and a 1090 from the same company in the same year. She has to wait until 2009. Of course, she actually retired (took the buyout offer), so maybe there's a difference. "

Might be company policy, we use retire folks as part time fill ins. They have to wait 30 days after the retirement date before they can come back.