flasher-3.5 -F RX-51_2009SE_10.2010.19-1_PR_COMBINED_MR0_ARM.bin -f

change kernel with
flasher-3.5 -F RX-51_2009SE_1.2009.42-11_PR_COMBINED_MR0_ARM.bin' --flash-only=kernel -f

Restore emmc with vanilla
flasher-3.5 -F RX-51_2009SE_10.2010.13-2.VANILLA_PR_EMMC_MR0_ARM.bin' -f -R

plug n900 in usb mode and copy/paste entire partition (+hiden file from emmc) to pc

flasher-3.5 --enable-rd-mode

on xterm make: sudo gainroot; sfdisk -d /dev/mmcblk0 > partition ; edit partition adn change mmcblk0p2 id to 76; sfdisk --no-reread /dev/mmcblk0 < partition ; reboot the phone.

now:

flasher-3.5 -F RX-51_2009SE_10.2010.19-1_PR_COMBINED_MR0_ARM.bin -f -R

now the phone say memory format not supported
open xterm; sfdisk -d /dev/mmcblk0 > partition ; edit partition adn change mmcblk0p2 id to 83; sfdisk --no-reread /dev/mmcblk0 < partition

now plug the phone in usb mode paste entire emmc from pc; reboot the phone;

and finaly the N900 works. if you want make:
flasher-3.5 -F RX-51_2009SE_10.2010.19-1_PR_COMBINED_MR0_ARM.bin -f
flasher-3.5 -F RX-51_2009SE_10.2010.13-2.VANILLA_PR_EMMC_MR0_ARM.bin' -f -R

I hope to be as explicit and can be helpful