the Extensions.mkext isnt important... only the permissions matter for booting into snow...

have u tried rebooting into snow? what error msgs do u get now?

btw, ive only tried this with a ps2 keyboard...

so could u unplug the ps2 mouse and see what happens with just the ps2 keyboard?

as a last resort try the following commands in terminal and try booting into snow:

chmod -R 755 /snowleo/system/library/extensions
chown -R root:wheel /snowleo/system/library/extensions
touch /snowleo/system/library/extensions

replace "snowleo" with your snow volume name...

if that doesnt do it, im sorry there's nothing else i can think of...