Let me begin my reply with *WARNING* - do not allow Enhanced Linux Kernel/'Kernel-power' to be removed by ANY application manager! If you do this, the phone will become stuck in a reboot loop (read on for solution).

My situation was as follows:

1. Upgraded stock N900 to 1.3.1. Current apps installed include BlessN900 and FCamera.
2. Installed Enhanced Linux Kernel.
3. Overclocking works.. camera doesn't ("Operation failed").
4. Tried removing all camera-related software - this does not fix the issue. Indicated solution in this thread is to enable extras-devel repository and upgrade the fcam-drivers package, using Faster Application Manager (FAM) to 1.7.2.
5. FAM says "Kernel-power" must be removed in order to install the upgrade.
6. Upon reboot, the phone is stuck in a reboot loop and will not boot up or charge.

If this happens to you - remove the battery immediately! N900 can't charge in this state and flashing requires good level of charge in the battery!

To resolve the problem a micro-USB -> USB cable and computer are required.

First grab flasher-3.5 from here: http://tablets-dev.nokia.com/maemo-d...-downloads.php . (Installation at the final phase, "Installing Connectivity Cable Driver", may take a very long time, be patient).
Then download the most recent firmware revision image (~190mb) for your locale: http://tablets-dev.nokia.com/nokia_N900.php.
Don't worry about the suggestions you may have read elsewhere about needing to reflash the whole OS - it should be possible to recover the phone in seconds as long as there is enough charge remaining in the battery to do so. I refer to the instructions here http://wiki.maemo.org/Kernel_Power#Deinstallation ..with this excerpt:

Open Command Prompt to the installation directory of flasher 3.5 and prepare the following command:

Re-insert the battery into your N900 and hold down the 'u' key on the keyboard. Insert the Micro-USB cable.

The display should activate without the backlight. When the USB icon appears at the upper right corner of the display, you may release the 'u' key and run the command you typed above. In a few seconds, the kernel is replaced.

Only the kernel will be replaced by this operation. If successful, you should be able to boot the phone with its kernel reverted to the stock version from the image. Camera functionality is restored

If unsuccessful, it may be because the battery's charge is too low (charge with another device or get hold of a battery with charge).

Alternatively, follow instructions elsewhere to attempt a full reflash.

I ensured all camera-related software was uninstalled and have installed Enhanced Linux Kernel again - camera functionality is maintained.


Hope this helps!

Alex