Forgot to say that for N800 device bootmenu supports only newer IT2007 version (2.2006.51-6). It may be that some early N800 devices in shops are still with older firmware 1.2006.47-20 which is currently not supported by bootmenu script. If you have this older version (check Control panel->Device->About) then I would be interested in /mnt/initfs/linuxrc file (before you upgrade) so I can add support for it.