Why after one year am I getting discoloration on some areas of preprimed finger jointed wood-work coated with a latex semi-gloss?
The most likely cause of the discoloration is the resin in the glue used to hold the wood together. An alkyd primer applied to the wood before the latex semi-gloss will usually lock this in, but sometimes you need to resort to an alkyd stain killer, or even a pigmented shellac stain killer in severe cases.