Good article on employer requirements upon 409A violation?

[Guest BL333]

Can anyone point me to a good article on what obligations an employer has upon a violation under 409A? Just for some reference, I am especially interested in this in the case of a stock purchase deal where the buyer figures out the violations post-closing? Looking for article discussing reporting, filing amended returns back to the date of the failure and any W-2 penalaties and penalities for not withholding or paying FICA taxes that might fall on the buyer.

Many thanks!