i used 6 different WM phones. non had this issue

you just didn't notice, and it is NOT an issue.
resistive touchscreen MUST flex to work, so ALL of your WM phones had flex when touched unless they were not resistive type of touchscreen you just didn't notice it is happening.

i got 4 devices in front of me and they ALL act same way, some more than others but they all do, if they didn't there would be no way to register touch input.

i understand screen must flex but on n900 it feels a lot more. i can live with it but it will be annying untill i get used to

The N900 has a haptic touch screen. It therefore needs to move to activate the haptics.

ummm, you do see how badly you fail here, don't you? assuming, for the sake of argument, that he didn't notice it on other devices, if your point (about it not being an issue) was to be valid, he would have to not notice it on the n900 either.

i tell you what does fail
people that don't understand how some technology works and then refuse to accept the facts when someone explains it all to them.

Last week it was very cold, and after beeing outside for a long time, the screen was doing a "click" sound when pressing it, as if the 2 layers were disassembling each other. I was very worried, but when I went inside with higher temperature in the room, the "click" disapeared, so maybe you had the same problem

you didn't explain anything. why didn't he have the same experience with other devices utilizing the same technology?

he didn't notice them? as in - they were there all along, but he unconsciously supressed that annoing sound in his fragile mind because it reminded him of his unhappy childhood? well, sir, that's one hell of a cluster**** of a fraudian mystery i tell you.

oh boy, i try again....
there is few different types of resistive touchscreens, n900 (as mikec said) uses haptic type, such touchscreen acts bit different then other resistive touchscreens, let me quote here something from n900 official features list: "The resistive touch screen includes haptic feedback so you know when you've pressed a key or onscreen menu"

so i recommend you read up about touchscreens variants before you post more nonsense.

hehe. nice try.

given several people have responded reporting they haven't experienced this on the n900, i'm willing to guess what the op is referring to is the same thing i've noticed: in certain conditions the plastic overlay is touching the lcd itself, and when it releases he hears a sound. i have the same problem, and i guarantee you, it's no feature nor any kind of intended haptic feedback implementation.