Vesting requirements for a short plan year prior to plan merger

[Guest McElroy]

A profit sharing plan with an 11/30 fiscal year-end is being merged into a 401(k) plan effective as of the close of business on December 31, 2000. The profit sharing plan will have a short plan year beginning December 1, 2000 and ending December 31, 2000. If the plan sponsor does not amend the profit sharing plan to provide for 100% vesting, do participants receive a vesting YOS if they work 1,000 hours in the period beginning December 1, 2000 through November 30, 2001 ans a vesting YOS if they work 1,000 hours for the period beginning January 1, 2001 and ending December 31, 2001? For all practical matters, doesn't this senario only require participants to be credited with an additional YOS for the one month plan year breginning January 1, 2000 and ending December 31, 2000. This could result in participants with profit sharing account balances having a greater vested percentae than they would have in their 401(k) amounts. Obviously, that would be the result if the plan were continuing as a stand-alone plan, but my case involves a merger.