We show that every resolution proof of the {\em functional} version
FPHP^m_n of the pigeonhole principle (in which one pigeon may not split
between several holes) must have size \exp\of{\Omega\of{\frac n{(\log m)^2}}}. This implies an \exp\of{\Omega(n^{1/3})} bound when the number
of pigeons m is arbitrary.