How do you keep your affection points from disappearing on Harvest Moon DS?

Affection points will only disappear if you do something to upset the person. For example, giving someone a rock or a weed will drastically lower their affection towards you. If this isn't the case then I'm 99% positive that it's because you are 'littering'. People in the Valley are VERY particular about littering. If you pick up a weed and drop it, that's considered littering. In fact, every time you drop an item you will lower everyone in the Valley's affection points. I tend to store items i would normally drop (such as weeds) in my pack and then toss them in my shipping bin later. You only get 1G per bush, but it keeps affection up and every bit money helps!

Also if your animals die it lowers your affection points so be careful!