I have been getting this error. I am currently running xubuntu 8.04.4 on a really old laptop. I can't seem to solve it the way apt is asking me to. Here is what I am getting:

kevin@kevin-laptop:~$ sudo dpkg --configure -a
[sudo] password for kevin:
Setting up linux-ubuntu-modules-2.6.24-28-generic (2.6.24-28.47) ...
update-initramfs: Generating /boot/initrd.img-2.6.24-28-generic
touch: cannot touch `/boot/initrd.img-2.6.24-28-generic.new': No such file or directory
/usr/sbin/mkinitramfs: 279: cannot create /boot/initrd.img-2.6.24-28-generic.new: Directory nonexistent
update-initramfs: failed for /boot/initrd.img-2.6.24-28-generic
dpkg: error processing linux-ubuntu-modules-2.6.24-28-generic (--configure):
subprocess post-installation script returned error exit status 1
Errors were encountered while processing:
linux-ubuntu-modules-2.6.24-28-generic

Any help in solving this problem would be greatly appreciated.