Depends on the plant, but the obvious contender is drought.

My first thought is drought too.

Thanks for your replies, but since you mention that it depends on the plant, Bamboo, I thought to give you a bit more information because I'm resonably sure that the plant has been kept well watered. It is an indoor plant called Anthurium kept in the sitting room that faces north, so no direct sun.

Oh, I remember your asking about this, and if I recall correctly, I gave you explicit instructions as to how to care for it, did I not? and did you carry out the remedial treatment I suggested (repotting, repositioning, etc)?

Yes Bamboo, you did and all the instructions were followed to the letter. The only problem now seems to be this one of the leaves dying back from the tip.

Is it possible that, now that we have much longer daylight hours, the sun is able to get onto the plant, when it wouldn't when the days are a little shorter? Otherwise, try misting it every 2 or 3 days as well as watering it that often.

Thanks Bamboo,
The plant is in a North facing room that gets no sun at all, so I will follow your misting/watering recommendations and keep an eye on it.