  It has been known for some time that the well established LMA solution to the
observed solar neutrino deficit fails to predict a flat energy spectrum for
SuperKamiokande as opposed to what the data indicates. It also leads to a
Chlorine rate which appears to be too high as compared to the data. We
investigate the possible solution to these inconsistencies with non standard
neutrino interactions, assuming that they come as extra contributions to the
$\nu_{\alpha}\nu_{\beta}$ and $\nu_{\alpha}e$ vertices that affect both the
propagation of neutrinos in the sun and their detection. We find that, among
the many possibilities for non standard couplings, only the diagonal imaginary
ones lead to a solution to the tension between the LMA predictions and the
data, implying neutrino instability in the solar matter. Unitarity requirements
further restrict the solution and a neutrino decay into an antineutrino and a
majoron within the sun is the one favoured. Antineutrino probability is however
too small to open the possibility of experimentally observing antineutrinos
from the sun due to NSI.
