Comment 1 for bug 809510

Thank you for taking the time to report this bug and helping to make Ubuntu better. While we appreciate the difficulties you are facing, it would appear that the CD image (ISO file) you downloaded could be corrupt.

Your log file shows the CD drive having trouble reading information, and the squashfs (compressed filesystem) containing the Live CD environment from which the environment is launched throws a lot of errors. here's a snippet of your syslog:

Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973822] sr 0:0:1:0: [sr0] Unhandled sense code
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973831] sr 0:0:1:0: [sr0] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973841] sr 0:0:1:0: [sr0] Sense Key : Medium Error [current]
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973852] sr 0:0:1:0: [sr0] Add. Sense: No seek complete
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973863] sr 0:0:1:0: [sr0] CDB: Read(10): 28 00 00 0e 33 cc 00 00 02 00
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973885] end_request: I/O error, dev sr0, sector 3723056
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973895] Buffer I/O error on device sr0, logical block 930764
Jul 12 07:08:08 bt5-stealth kernel: [ 1230.973903] Buffer I/O error on device sr0, logical block 930765
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.444851] SQUASHFS error: squashfs_read_data failed to read block 0x719b6ea6
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.444861] SQUASHFS error: Unable to read metadata cache entry [719b6ea6]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.444868] SQUASHFS error: Unable to read directory block [719b6ea6:1c52]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.444921] SQUASHFS error: Unable to read metadata cache entry [719b6ea6]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.444928] SQUASHFS error: Unable to read directory block [719b6ea6:1c52]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.445137] SQUASHFS error: Unable to read metadata cache entry [719b6ea6]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.445145] SQUASHFS error: Unable to read directory block [719b6ea6:1c52]
Jul 12 07:08:08 bt5-stealth kernel: [ 1231.445170] SQUASHFS error: Unable to read metadata cache entry [719b6ea6]

 There is an easy way to verify the integrity of the Ubuntu ISO files you download. Could you please visit https://help.ubuntu.com/community/HowToMD5SUM follow the instructions and report back as to whether or not the MD5SUM verified? Thanks in advance.

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