not neccessary, I had that happened to me couple of time w/ nothing else install, other than RX-34_2007SE_3.2007.10-7_PR_COMBINED_MR0_ARM.bin
The only changed I made was setup my wifi and adding RSS feed. After I go grab the rss, the system crash and went into continuous reboot.

This may or may not help, but what I found out was that if I have dualboot, and boot into another OS, it will work, so it's definitely not the kernel issue, because they shared the same kernel, what I did found out also is that, if I run
"fsck.ext2 /dev/mmcblk0 -f", there seem to be something corrupted in the filesystem. If I continue rebooting, it get worse. The last time I check there isn't any fsck.jffs2, so if the jffs2 fs got corrupt, then there is noway to fix it other than reflash. which to me look a lot like what happened and cause the system to be in reboot loop.

Well,they say everything about iPhone but I'm really proud to own N800. Its spectacular!!

If you are having booting problems don't worry so much since it's just a software problem.

I'll advice you to reinstall the operating system again by downloading

1.Nokia_Internet_Tablet_Software_Update_Wizard.exe

2.dotnetfx.exe

3.RX-34_2007SE_3[1].2007.10-7_PR_COMBINED_MR0_ARM.bin

I don't have to upload all these again since I downloaded everything from here.

First install #2 and #1 on your windows PC. Yeah you don't have to own a Linux PC b4 reinstalling OS.

Now run the installed wizard and follow the instructions. Now when the wizard ask you to download the new firmware say no and choose browse to install the OS from your hard dirve. It's very fast.

Now, don't you worry about your lost applications as maemo got it all, just take sometime to download these apps.

I'm proud to have control over my N800.

Good Luck!!

I think that there are serious problems with the cable in the package- I tried to use it to reflash dozens of times, and it just would not work.

The above instructions do work- but only worked for me when I located a Kodak digital camera mini usb cable and used it to plug into the N800- and that was only after downloding the OS2007 to my hard disk, doing a full disk defrag, shutting down all other applications on my machine, and plugging to the back USB on my Unit (Windows XP System).

My OS2007 works fine now, and I have both installed SD cards reading on the unit again-

This is a brutal process- I would advise ALL with new machines to NOT download OS2008 as of yet, as in wait until Nokia gets this whole mess on reflashing straightened out and simplified and gets you replacement cables- <if your reflash messages say there is something wrong with the USB Port or cable, it is likely the cable>.

If you Do Try a reflash attempt- only attempt it once or twice and on a FULL battery, because if your battery is drained it will only get you into the endless reboot of the death screen. Once that happens you do not and cannot know what level of charge your unit is at.

If/when that happens, charge overnight, then unplug, and take the battery out/reinsert (should be near full charge then, even if the screen has been rebooting all night), then follow all of the above steps- with a NON Nokia (ie Kodak Easy Share) type mini USB cable. Switching off all other interfering applications and defragging your hard disk before the attempt should help as well-

ok, guys, i've gotta get some help for this one.
i've been experiencing the stagnant NOKIA screen at bootup (with no rebooting). i figured i could just reflash it. however, upon trying to hook up to my girlfriend's winxp computer, it will only connect via usb for a second, then disconnects me and the screen stays at the NOKIA screen. so, i can only assume that i cannot reflash my os. is this correct? before this problem occurred, the n800 was working fine, and when i grabbed it to leave for the day, the system just froze, will not reboot, and will not connect to the pc. what can i do? i haven't had much luck searching this forum or the web.
awakenist.