1. A method of reading a plurality of data bits that are stored in a memory that includes a plurality of multi-bit cells, the storing being effected by computing a plurality of parity bits that correspond to the data bits and then storing the data bits and the parity bits in the cells of the memory as stored bits, the method comprising the steps of: (a) reading the cells, thereby obtaining a plurality of read bits; and (b) correcting said read bits that correspond to the data bits, in accordance with said read bits that correspond to the parity bits, wherein said correcting is effected at least in part by decoding said read bits, said decoding using, as initial reliability estimates for at least two of said read bits, a priori estimates of respective probabilities that said at least two read bits are erroneous, wherein said a priori estimates are independent of values of said read bits, and wherein at least one said estimate is different from at least one other said estimate.