Comment 4 for bug 356095

uname -a:
2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:10:02 UTC 2010 i686 GNU/Linux

W/ Lucid Lynx I had the same problem. I was trying to install JUST to the external USB drive but apparently Grub was written to the internal drive. So now the previous working Grub(legacy) on the internal drive is overwritten by a Grub2 menu that won't boot if I don't have the external USB drive plugged in(!) I'm lucky I'm not a complete novice user (which is exactly what the user-friendly look and feel of Lucid Lynx and beyond will start pulling in), or I'd be completely petrified right now. Even as it is I'm a long way from knowing how to restore my system.

2.6.32-21-generic #32-Ubuntu SMP Fri Apr 16 08:10:02 UTC 2010 i686 GNU/Linux

I think if the user is not given a choice where they want Grub to go, then the default assumption should certainly be to the drive they are installing to, and no dependency should be created to any other drive. If you want to provide an "advanced options" to put Grub somewhere else, whether it should include other drives/partitions, etc. well that's fine, but at least for the default and for beginning Ubuntu users they should not be faced with a Grub recovery prompt after removing a USB drive they just installed to(!!!).