This excerpt taken from the MSCS 10-K filed Apr 17, 2006.
(B) Last Day Employment Requirement. If the Plan is a Standardized Plan, a Participant who is employed by the Employer on the Accounting Date of a Plan Year will share in the allocation of Employer contributions for that Plan Year without regard to the Participants Hours of Service completed during that Plan Year. If the Plan is a Nonstandardized Plan, the Employer must specify in its Adoption Agreement whether the Participant will benefit under the Plan if the Participant is not employed by the Employer on the Accounting Date of the Plan Year or other specified date. If the Plan is a Nonstandardized money purchase Plan or target benefit Plan, the Plan conditions Employer contribution allocations on a Participants employment with the Employer on the last day of the Plan Year for the Plan Year in which the Employer terminates the Plan.