take a good guess what your previous kernel was (any you had on the system for which you didn't deinstall the modules - if you don't know: try and pray )

download it from the repository.

http://repository.maemo.org/ (i never remeber there was one with the kernels as images. but if not you can use ar to open the deb and will find the fiasko in the deb)

flash it.
http://wiki.maemo.org/Updating_the_tablet_firmware
(the description should guide you just remamber that only want to flash the kernel so you need the "-k" !)