Concurred with kingoddball. Honestly, I've been using my N900 from day one with this problem, and honestly, it never bothered me. It's certainly not enough to make me jump ship to the iPhone 4 or whatever else the next new shiny thing will be, when the N900 is practically the god of phones in terms of versatility right now.

It falls within the nokia warrenty and can be demanded for a repair.

The person i spoke from the nokia care center told me it mostly has to do with water damage. The n96 also had this problem allot he said.

Something i didn't know is that every nokia has a water indicator on it. wich makes it possible for nokia to see wether or not a phone has had water damage in the past. the guy there told me that.

If i were you, and your n900 has not had water damage, i would bring the n900 in for repair. It didnt bother me in the first place but it looked like it became worse, and i started to anoy the fact that my 600 dollar device didn't have a descent screen.

I have the exact same spots but had no water damage. My phone is getting very hot (51°C battery temp) due to overclocking.

Could it be that some things "melt" behind the screen?

I dont think so. most people i know, who have this problem, have this from the day they bought it... at that point there wasnt even an overclock option yet. Second of all the screen has an iron plated back panel and space between, the CPU and chips are on the bottom part of the phone (behind the keyboard) so would be very strange if that was the problem.

I think its an error in the production process. witch the back layer ist fully atached to the screen and gives some kind of bubbles between, wich gives a strange white spot when backlight shines at it.

Mine had 2 spots and 5 dead pixels in a row. I think mine was built on a monday morning.

got the two lower spots on my display as well. they don't bother me but I'm curious to their origin as well

Have the exact same issue. I only noticed these spots couple of weeks ago, when played Beneath a Steel Sky under ScummVM due to a lot of pixel hunting involved. Not sure if the spots were there before.
They're unnoticeable enough, so I forget about them from time to time. Still not great they are here, but I can live with it.

I have this too, and I haven't had any water damage

So its seems like a bigger problem then everyone is saying. i think the problem of it not officially recognised by nokia is due to the very few people who actually turn their n900's in for repair.

As i understand from this thread lots of people dont care that their 600 dollar device's screen falls apart.

I can also confirm that heat makes the issue worse. i think what you see is an air bubble that when heated gets bigger wich makes the visibility of it worse.

I just want it to be fixed! i think its not supposed to be there. Nokia needs to make good quality screens! not one that falls apart in the device. I also think its ridiculous that nokia writes in its manual that dead pixels are never a warranty issue. i have 5 on the middle of the screen. and they are very anoying. I think a screen needs to be perfect 100% because thats where everything happens. ever watched a movie on the n900 with a row of dead pixels? well it annoys me allot!

i have a white spot on my screen aswel.

I've also got the two lower spots. Up until now I thought I had accidentally hit the screen with something but I guess not. No water damage, no overclocking or heating issues - just those two spots.