Thanks for all the advice. I'm a bit worried about the comment re lead paint as I have a little 14mth old lad I'll have to be really careful if I remove any paint but to be honest I'll probably only take off the top layers or I'll replace the wood.
We have a dilema. We have an oldish house (1938) and we are trying to decide whether to replace our existing door frames or remove the existing paint. One side of me says just rub down the existing paintwork (but not down to the wood) and repaint. This looks like it would be OK for the flat surface ...