"Commingling" plan's retirement and death benefits in a sing

[KJohnson]

Participant and Spouse participate in the same Plan. Participant begins taking minimum required distributions from Plan based on a single life. Participant subsequently rolls the remaider into an IRA where she has to continue on a single life basis under the 401(a)(9) proposed regs.

Participant's spouse dies. Participant rolls the death benefit into the same IRA. Can participant take distribuitons from the "death benefit" portion of the IRA based on joint lives while continuing to take single life for the "retirement" portion of the IRA?