if you uninstall power kernel through Ham you effectivley delete the kernel from your phone, you should of used the unistall power kernel package.

Bad mistake to make, i know as i did the same without thinking!!

There is an art to getting the phone into flash mode and re flashed, it took me 5 or 6 attempts to get it right

Download flasher 3.5
Download the currect kernel version & move to the flasher application folder
Type command as stated in the wiki, DONT execute the command yet
Ensure battery and USB cable are out of N900
Hold U on the key board, replace battery, insert USB and start phone - DONT let go of the U key until the nokia logo is visible but against a black screen, this means the phone is in flash mode
Execute the command previously prepared.
A kernel reflash message should return complete within 10 seconds.
Unplug your phone and reboot
Job done

http://wiki.maemo.org/Updating_the_t...a_FIASCO_image

good luck