grub fails to detect RAM size correctly

I have a Pentium machine with 64 megs of RAM (although only 56 megs are actually usable), running Breezy. GRUB fails to detect the memory size correctly (it finds 7 megs of extended memory) and complains that that is not enough to boot an Ubuntu kernel.

I can get it to boot by editing /boot/grub/menu.lst, adding mem=56M to the '# kopt=' line, running update-grub, and then adding 'uppermem 56320' before each kernel entry in the 'AUTOMAGIC KERNELS LIST' section. (Adding the uppermem line once at the top of the file was not enough to fix the problem). This is not convenient, as I have to remember to manually edit menu.lst every time after a kernel upgrade.

Longer story: https://lists.ubuntu.com/archives/ubuntu-users/2006-January/063603.html

Purpose of this bug report: I would like GRUB to be able to detect the memory size correctly (memtest is able to do so, syslinux and LILO, apparently, also). If that turns out not to be possible, I'd settle for a way to specify memory size once in a way that dispenses with the requirement to manually edit menu.lst after every kernel upgrade.