Although not strictly Debian/ppc releted (==gentoo), but is this known problem with ppc/ppc64 and 2.6.* kernels?
> > When mke2fs is used for big partitions ( >= 80-100 GB) > kernel panics everytime with message: > > Bad page state at prep_new_page: (in process 'mke2fs', page > c000000000889c00) > -- IsoH