return of after-tax contribution made lasta year?

[Guest jy12443]

If, due to an administrative error, an after-tax contribution was made to a 401(k) plan after the employee asked that no further contribuitons be made, can such amount be returned to the participant (with the employer contribution made on such amount being forfeited)? I would say yes, b/c it was admittedly the recordkeeper's error -- but, the contribuiton was made in 2007. Any issue with refunding this now for a mistake made last year?