multiple LUNs usb disk drive does not mounts CDROM LUN on 12.04 (works on 11.10 and older)

[Giuseppe Amato]

My company produces an USB Flash Disk drive device using a controller capable of managing multiple partitions LUNs (logical units).
When using dual LUN, first in CDROM emulation mode and second in normal removable disk R/W mode, only the R/W partition gets automatically mounted by the system.
The CDROM partition istead is not mounted automatically, but correctly appears in /dev/ as "sr0".
I'm able to use the CDROM partition if I manually mount it using a command similar to:
# mount -t iso9660 /dev/sr0 /mnt

the problem is present only on Ubuntu 12.04LTS.
11.10 is not affected at all.

I'm available to make any test and to collect any info you may need to solve this issue.

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: udisks 1.0.4-5ubuntu2
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic i686
ApportVersion: 2.0.1-0ubuntu5
Architecture: i386
Date: Thu Apr 26 16:28:56 2012
DistributionChannelDescriptor:
 # This is a distribution channel descriptor
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-guandu-20110429-8
EcryptfsInUse: Yes
HotplugNewDevices: /dev/sdc /dev/sdc1
HotplugNewMounts: /dev/sdc1 /media/0000-0001 vfat rw,nosuid,nodev,relatime,uid=1001,gid=1001,fmask=0022,dmask=0077,codepage=cp437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro 0 0
InstallationMedia: Ubuntu 10.10 "Maverick" - Build i386 LIVE Binary 20110429-13:50
MachineType: ASUSTeK Computer INC. 1015PX
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.2.0-23-generic root=UUID=bd118085-12ec-44c8-94d8-c51183fc5073 ro quiet splash vt.handoff=7
SourcePackage: udisks
Symptom: storage
UpgradeStatus: Upgraded to precise on 2012-04-16 (9 days ago)
dmi.bios.date: 08/30/2011
dmi.bios.vendor: American Megatrends Inc.
dmi.bios.version: 1401
dmi.board.asset.tag: To Be Filled By O.E.M.
dmi.board.name: 1015PE
dmi.board.vendor: ASUSTeK Computer INC.
dmi.board.version: x.xx
dmi.chassis.asset.tag: 0x00000000
dmi.chassis.type: 10
dmi.chassis.vendor: ASUSTeK Computer INC.
dmi.chassis.version: x.x
dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1401:bd08/30/2011:svnASUSTeKComputerINC.:pn1015PX:pvrx.x:rvnASUSTeKComputerINC.:rn1015PE:rvrx.xx:cvnASUSTeKComputerINC.:ct10:cvrx.x:
dmi.product.name: 1015PX
dmi.product.version: x.x
dmi.sys.vendor: ASUSTeK Computer INC.

[Giuseppe Amato (midori3)]

An update:
running the "lsblk" command line tool the CDROM gets magically automounted.
I think that this provide usefull information on finding the bug in udisks daemon.