I've got a newer firmware: ver.req - I tried switching the output format to PAL and it made no difference. I have firmware GM1.00C:

Canon PowerShot A1100 IS
P-ID:31C3 NT D

FirmWare Ver GM1.00C
NoError
Apr 24 2009 19:12:45

After another press, I have 4.011:

Adj Ver.004.011

The third and fourth screens are the same as everyone else's:

IS Firm Ver. 2.11
IS Param Ver. 2.07

Driver Info: 0x00000000

With vers.req I get:

Canon PowerShot A1100 IS
P-ID:31C3 NT D

FirmWare Ver GM1.00C
NoError
Apr 24 2009 19:12:45

Second press (4.011):

Adj Ver.004.011

Third press (shoot count):

Adj Ver.004.011
Total shoot: 2
Zoom retry count: 0
Mecha Condition: 0x00000000

Fourth press:

Driver Info: 0x00000000

--Dch24 19:29, November 6, 2009 (UTC)

I'm trying to install udumper with this shell script:

#!/bin/bash
if [ -z "$1" ]; then
        if ! which hdiutil >/dev/null 2>&1; then
                echo "Please specify which partition to modify"
                echo "  for example: $0 /dev/sdh1"
                exit 1
        fi
        # hdiutil is a Mac OS utility - we can auto-detect the partition
        if ! mount >/dev/null 2>&1; then
                echo "cannot run mount:"
                mount
                exit 1
        fi
        if ! mount | grep -q UD_; then
                echo "Please format a FAT-16 partition and name it UD_something"
                exit 1
        fi
        PART="`mount | sed -e '/UD_/s/^\([^ ]*\) .*/\1/p;d'`"
        echo "Checking ${PART}..."
        if ! hdiutil unmount "$PART"; then
                echo "Failed to unmount $PART"
                exit 1
        fi
else
        echo "Reading partition $1:"
        PART=$1
fi
if ! dd if=$PART bs=1 count=8 iseek=54 >/dev/null 2>&1; then
        echo "Failed to read partition type from $PART"
        if which hdiutil >/dev/null 2>&1; then
                hdiutil mount "$PART" # at least try to re-mount it
        fi
        exit 1
fi
PTYPE="`dd if=$PART bs=1 count=8 iseek=54 2>/dev/null | \
        hexdump -e '8/1 "%02x "'`"
r=$?
if [ "$r" != "0" ]; then
        echo "Failed to decode partition type"
        if which hdiutil >/dev/null 2>&1; then
                hdiutil mount "$PART" # at least try to re-mount it
        fi
        exit 1
fi
if [ "$PTYPE" != "46 41 54 31 36 20 20 20" ]; then
        echo "Partition type is not FAT16 - abort"
        if which hdiutil >/dev/null 2>&1; then
                hdiutil mount "$PART" # at least try to re-mount it
        fi
        exit 1
fi
echo "Modifying boot sector on partition $PART ... THIS IS DANGEROUS!"
echo -n "Press CTRL-C now to quit (or press ENTER if you are sure) : "
read
# offset 43 (0x2b, volume label), write "EOS_DEVELOP"
echo -n "EOS_DEVELOP" | dd of=$PART bs=1 oseek=43
# offset 64 (0x40), write "BOOTDISK"
echo -n "BOOTDISK" | dd of=$PART bs=1 oseek=64
if which hdiutil >/dev/null 2>&1; then
        echo "Mounting $PART again:"
        hdiutil mount "$PART"
fi