I did a reflash recently and here are the instructions I followed:

Setting Maemo device to flashing mode

For Nokia N900 with a Fremantle image, flashing mode can be enabled by following these steps:

1. Switch off the Maemo device
2. Press and hold down the 'u' key
3. Connect a USB cable between the Maemo device and host PC while holding down the 'u' key
4. When the USB cable is connected, it powers the Maemo device and sets it to flashing mode
5. When the USB icon appears in the upper right-hand corner, the Maemo device is in flashing mode
6. Release the 'u' key

If performed correctly, the USB image is visible in the upper right-hand corner of the screen.

The Maemo device waits indefinitely for Flasher-3.5 input when it is in flashing mode. If flashing is tried without first setting the Maemo device to flashing mode, image flashing may fail because the Maemo device may not be able to change to the flashing mode automatically.

The command to use: flasher-3.5.exe -F RX-51_2009SE_20.2010.36-2_PR_COMBINED_MR0_ARM.bin -f -R

It will take about 2 minutes, and there will be a lot of action on the screen in the command prompt window.

I hope that helps.

I can't get the usb icon to appear in the upper right corner anymore after step 3. It just shows the dimmed Nokia logo at first and then switches to the brighter white screen with Nokia logo but still without the usb icon. This keeps repeating like this. It goes dark for two seconds then two seconds white and so on. The flasher just sits there waiting for a suitable device

I have to take out the battery to get it out of that crazy booting behaviour.

Bump......

Do you think it's bricked?