No deferrals on bonus pay

[cpc0506]

What are the suggested options in the following scenario:

A plan did not defer bonus payments according to the participants deferral election in 2009 or prior years; for example 0% was withheld from a bonus UNLESS a participant made a special election to defer from the bonus. The special election should have been the other way. The standard amount should have been withheld UNLESS the participant requested a different amount.

Would they have to make a correction?

Could they make the change moving forward only?

Thanks for any guidance on this issue.