QUOTE(pianodub @ Nov 6 2009, 10:14 PM)

Hi,
This is a big challenge for piano teachers. If I understand you correctly your son's fingers are collapsing at the top joint on contact with the keys. This is probably because they are not sufficiently strong. Pupils often find ways to compensate for this as they progress. If you think about it, this part of your finger really doesn't have to work in the rest of your life! I would suggest a few tactics to strengthen them up:
Try making an oval shape (hard to describe without showing?!) between your fingers one at a time and your thumb. One at a time, tap your fingertip and thumb together three times.
When he can do this, try doing two taps and a press. He can do this is school or while watching tv etc.
He could also try practising his scales HS, very staccato, almost playing on his nail. Mind he doesn't lift his shoulder/arm doing this, aim just to maintain a good wrist position and pull the fingers in. Do this SLOWLY!!! Remember to be relaxed.
If 2 and 3 are a big problem, he could practise playing scales using these fingers only.
The 5th finger is often a problem. This is sometimes fixed by having your thumbs in over the keys and curved...the 5th finger then often naturally fixes itself.
Keep in mind he doesn't need to be right up on his fingertips all the time, different positions lead to different sounds and the most important thing is that he is not playing with any tension as this can cause big problems later on.
pianodub:
I get what you mean. Will get my son to try it.
His 2 and 3 are very obvious especially during scales (descending)
Mad Tom:
Yup, his teacher noticed this problem recently and wanted him to correct them. In fact, he has this problem few grades ago.... I have been reminding him to change for quite sometime now.
Thanks for the quick response, pianodub and Mad Tom.