[TriLUG] [eee] post-install, grub OK from external stick but not from internal SSD

[Tom Roche]

summary: my eee comes with eeeXandros installed on its internal flash
drive, to which I could previously boot NP. I installed eeeXubuntu to
an external USB stick. Now I can boot with the stick inserted (though
only one way) but I can't boot without the stick (which I really need
as an option), and even booting with the stick is problematic. How to
fix?

details:

I want to be able to boot my eee

0 from its SSD (internal flash drive), i.e. with no external drives
   attached

1 from an external USB stick with a different OS

After editing the stick's menu.lst (as described @

http://www.trilug.org/pipermail/trilug/Week-of-Mon-20080421/054121.html

) I can boot either to the eeeXubuntu on the stick (/dev/sdc1) or to
the eeeXandros on the SSD (/dev/sda1). But I can only do that by

* inserting the stick <duh/>
* hitting Esc after BIOS startup
* choosing to boot from the stick
* choosing the desired target (stick or "Normal Boot" from the SSD)

but I can't boot either

- without the stick inserted. This I really need, for obvious reasons.

- with the stick inserted, but choosing the SSD from the BIOS' Boot
   Selection Popup. This would be nice, but is gravy.

If I do [shutdown, remove the eeeXubuntu stick, power on], I get

 > GRUB Loading stage1.5

 > GRUB loading, please wait...
 > Error 21

and no opportunity to enter the grub editor (am I missing something?).
If I do [shutdown, insert the eeeXubuntu stick, power on, select the
stick from the Boot Selection Popup, select "" from grub], I can boot
eeeXandros and see the SSD's /boot/grub/menu.lst, which has

root (hd0,0)

which looks right to me based on the previous experience, i.e.

http://www.trilug.org/pipermail/trilug/Week-of-Mon-20080421/054121.html

but obviously isn't working. How to fix?

TIA, Tom Roche <Tom_Roche at pobox.com>