Updating 9.10 netbook remix on external usb drive (FAT32)

[Observer]

Binary package hint: grub2

Hello,
I'm a Linux newb so feel free to delete the report if it is of no interest for the developers.
I've just installed Ubuntu 9.10 Netbook Remix to an old 20GB drive in external USB enclosure (the installer only used the DVD-sized 4.5GB of that FAT32 space). There was also an internal HD with same distro installed on it but not mounted during the update. When prompted by the update manager I selected the USB drive (devb or something like that). Attached is the error message I've got.
Thanks to the developers and shalom from Israel.

ProblemType: Package
Architecture: i386
Date: Sat Feb 27 13:02:50 2010
DistroRelease: Ubuntu 9.10
ErrorMessage: subprocess installed post-installation script returned error exit status 1
LiveMediaBuild: Ubuntu-Netbook-Remix 9.10 "Karmic Koala" - Release i386 (20091028.4)
NonfreeKernelModules: nvidia
Package: grub-pc 1.97~beta4-1ubuntu4.1
ProcVersionSignature: Ubuntu 2.6.31-14.48-generic
SourcePackage: grub2
Tags: ubuntu-unr
Title: package grub-pc 1.97~beta4-1ubuntu4.1 failed to install/upgrade: subprocess installed post-installation script returned error exit status 1
Uname: Linux 2.6.31-14-generic i686

[Colin Watson (cjwatson)]

If you're still experiencing this problem (sorry for the delay!), then please use root privileges to edit /var/lib/dpkg/info/grub-pc.postinst and change the "-e" on the first line to "-ex"; then run 'sudo dpkg --configure grub-pc' and copy-and-paste the output into this bug. Thanks in advance!

[Brian Murray (brian-murray)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 557023, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Please continue to report any other bugs you may find.