  In this paper, we prove a stability result on k mod p multisets of points in
PG(2,q), q = p^h. The particular case k=0 is used to describe small weight
codewords of the code generated by the lines of PG(2, q), as linear combination
of few lines. Earlier results proved this for codewords with weight less than
2.5q, while our result is valid until cq sqrt(q). It is sharp when 27<q square
and h>=4. When q is a prime, De Boeck and Vandendriessche constructed a
codeword of weight 3p-3 that is not the linear combination of three lines. We
characterise their example.
