Sorry for not noting that zz-update-grub belongs to grub-legacy.
The version i'm using is 0.97-62.
In the zz-update-grub script there's a problem with some arguments
between single quotes that makes unmatch the case condition.
The attached patch solves the problem.
Ciao.
Cesare.
--- zz-update-grub 2010-08-04 04:41:37.000000000 +0200
+++ zz-update-grub-patched 2010-08-20 03:27:59.000000000 +0200
@@ -2,8 +2,8 @@
set -e
set -- $DEB_MAINT_PARAMS
-mode="${1#'}"
-mode="${mode%'}"
+mode="${1#\'}"
+mode="${mode%\'}"
case $0:$mode in
# Only run on postinst configure and postrm remove, to avoid wasting
# time by calling update-grub multiple times on upgrade and removal.
