She has updated the OS again (from the phone) and now everything is OK

Thats incorrect, the exact same thing happend to me, as soon as I took it ouf of the box within 2 minutes it was restarting!

Updated the phone in ~ 15th Jan - and no problem since!

It's was a driver fault I believe, not h/w

My phone rebooted the first time I switched it on, but not again since.
Everythings working fine, nothing major.

The thread "My sister bought one and it is restarting every 10minutes!" with twenty-three posts has been merged into this thread.

I have never installed Maemo 6 UI Demo nor extras-devel repository and yet I get about 5-10 reboots per day (PR 1.1.1 / 2010.02-8 via OTA updates) and sometimes even more under heavier use.

Sometimes the reboot occur under 3 minutes of use, just opening a web browser. Sometimes it happens when I'm rearranging things on Contacts. Truly erratic.

Will reflash the whole device when PR 1.2 comes out. But if that still won't fix it, I'm not sure what I'm gonna do with this device... :-(

Format N900 internal memory, reflash N900, this will fix it.

What's the proper way to reflash the device entirely?

When I go to http://wiki.maemo.org/Updating_the_tablet_firmware it says I have to distinguish between UK variant and standard variant. My N900 has UK default locale and UK plugs, but says "Made in Korea" so is it UK or non-UK ?

And lastly, the PR1.1.1 firmware is not available (as of March 16, 2010) for UK variant so does that mean I can only use PR1.1)? Or is there another way e.g. NSU ? (I also don't understand what's the difference between flashing and using NSU)

It's just made in Korea, but it's made for the UK (so it's a UK variant).

Flashing = same as NSU (flashing is for advanced users).

Try this:

1 - Format the internal n900 memory and then flash with NSU

2 - the above should work if it doesn't then follow the wiki instructions and flash eMMC and main OS, just use GLOBAL variant or EU, it doesn't make much difference.

Hi guys, reading this thread, made my day.
Some days ago, i bought a N900 with some problems...problems like, random reboot, with some versions of FW, i cant use my sim card, with other, i cant use his internal memory.
The crazy thing is this: I use for example the first fw for US, and i get no sim card.
Tomorow, if i install the same FW, i cant access the mass memory, or random reboots.
Ive tryed to format the massmemory, reflash eMMC, reflash the FW, like 20 or 30 times via USB or OTA, but the problems are still bothering me.
What made my day? Now i know i'm not the only one with the random reboot problem
I hope NOKIA is reading this thread, and is cooking something good for our phones.
Best wishes.

My Dec08 N900 did not have the 32wd reboot problem, until I downloaded some stuff from the Dev. repository. One tool I downloaded showed me the reboot reasons to be 32wd. I also noticed the Settings "About Product" screen was defect as it showed me dots.... where Nokia N900/Maemo 5/Version: 3.2010.02.8 was to be AND my Screen calibration would NOT work anymore (it would disappear immediately when the screen was touched for calibration.
So I flashed about 3 times utilizing the RX-51_2009SE_3.2010.02.8 bin.
When installing the apps using Restore applications in Ap Man I gradually deleted more and more dev. programms from being reinstalled.
I have now established that Powatool is the permanent culprit for the Callibration problem. All was well - then installed Powatool only - and calibration failed - uninstalled Powatool and calibration remained broken. The About Product is still OK - have not had a reboot since, but still to early for final conclusion. 3rd time flash deleted also the selection of quite a number of Dev. Rep. tools, such as the Boot Reason tool and the Outside IP tool, also the 2 Kernel "flashes" do not show up after the 3rd flash. It was my unfounded deduction that these Kernel adjustments would be the culprit for the 32wd reboots (which were at an alarming rate, maybe after Ooooopses, but did not have time to establish that as the flashes have taken away some of the GUI tools I used to see what was wrong and being a Noob I don't want to get involved with Serious X-Term work).
Should the reboots start again, I will report and flash again and then not install Powatool again to keep calibration working properly to see if Powatool is also the culprit of the 32wd reboots that started to happen after 3 month N900 use. So for me definately not a Hardware problem, unless it developed recently in conjunction with Dev-Repos. downloads.
But in establishing what Powatool has done, it's my guess the reboots have to do with Dev-Repos software I downloaded. (the downloads involved are mainly still in my Ap.Man. restore application list, so a list is available should Powatool not create the reboots too. Health Check gives me 0 bootcounts at present.)
So far my 2P