It seems we have all experienced the cats unusual attitude to water...

Mine don't like bowls or sauces and will only drink water out of glasses or mugs, wether it is old or not doesn't seem to worry them - as long as it is in the correct vessel.

...unless it's not meant to be drunken - like a slow running/dripping tap in the bathroom, the drops left in a bath or shower, the little water streams accross the courtyard after watering.

I suggest you fill several different vessels with water and leave them around the house in different spots and see which one(s) Pui Pui likes.

By the way, what does "Pui Pui" mean and in what language?