EDIT: is the charger connected when you are booting? There used to be some issues with multiboot where it wouldn't boot correctly when charging. It should have been fixed but it's worth disconnecting from your charger if Maemo isn't booting. If you can't boot any OS, you are going to need a re-flash. How did you install, SD card or eMMC? If you used the SD card, your mulitboot item for NITDroid would be mmcblk1px if it's eMMC then is should be mmcblk0p5. The auto installer will create the correct items for Maemo which do not need to be changed.