/boot too small, how to fix?

1. move /boot contents

   mkdir /boot2
   rsync -a /boot/ /boot2/
   umount /boot
   rmdir /boot
   mv /boot2 /boot
   

2. install Debian's standard kernel to help with a lot of initrd stuff in the background

   apt-get install linux-image-amd64

3. create your new kernel's initrd if not yet done (3.2.17-atlas in this example):

   update-initramfs -c -k 3.2.17-atlas

4. re-install/update grub (here on first hard drive's MBR)

   grub-install '(hd0)'
   update-grub
   

5. Ensure grub is installed correctly (i.e. look for set root and if the initrd line is present for your kernel)

   less /boot/grub/grub.cfg 

6. Finally, remove /boot from /etc/fstab and then you should be ready to reboot.