  We study influence of electron-electron interaction on statistics of Coulomb
blockade peak spacings in disordered quantum dots. It is shown that the
interaction combined with fluctuations of eigenfunctions of the Fermi sea,
enhances the peak spacing fluctuations, in accordance with recent experiments.
In addition, account of the spin degrees of freedom leads to a pronounced
odd-even structure for weak interaction ($e^2/\epsilon \ll v_F$); in the
opposite case ($e^2/\epsilon \gtrsim v_F$) this structure is washed out.
