Canon FB636u does not acquire images

I'm not sure whether this is a kernel issue or a sane issue.

$ uname:
Linux hb 2.6.27-7-generic #1 SMP Fri Oct 24 06:42:44 UTC 2008 i686 GNU/Linux

Hardware: HP nx8220, Canon FB636u

$ sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

found USB scanner (vendor=0x04a9, product=0x2204 [CanoScan FB630U]) at libusb:002:006
  # Your USB scanner was (probably) detected. It may or may not be supported by
  # SANE. Try scanimage -L and read the backend's manpage.

  # Not checking for parallel port scanners.

  # Most Scanners connected to the parallel port or other proprietary ports
  # can't be detected by this program.

  # You may want to run this program as root to find all devices. Once you
  # found the scanner devices, be sure to adjust access permissions as
  # necessary.

$ lsusb
Bus 004 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 006: ID 04a9:2204 Canon, Inc. CanoScan FB630U
Bus 002 Device 003: ID 03f0:011d Hewlett-Packard Integrated Bluetooth Module
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 003: ID 05ac:0304 Apple, Inc. Optical USB Mouse [Mitsumi]
Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub

$ scanimage -L
device `canon630u:libusb:002:006' is a CANON Canoscan FB630U flatbed scanner

$ SANE_DEBUG_CANON630U=12 scanimage > img.png
[sanei_debug] Setting debug level of canon630u to 12.
[canon630u] sane_init: version_code != 0, authorize != 0
[canon630u] sane_init: SANE Canon630u backend version 1.0.1 from sane-backends 1.0.19
[canon630u] reading configure file canon630u.conf
[canon630u] attach_matching_devices(usb 0x04a9 0x2204)
[canon630u] attach_scanner: libusb:002:006
[canon630u] attach_scanner: opening libusb:002:006
[canon630u] CANON_open_device: `libusb:002:006'
[canon630u] CANON_close_device:
[canon630u] finished reading configure file
[canon630u] sane_get_devices(local_only = 0)
[canon630u] sane_open
[canon630u] sane_open: devicename=libusb:002:006
[canon630u] CANON_open_device: `libusb:002:006'
[canon630u] sane_control_option: handle=0x9204c08, opt=0, act=0, val=0xbfe87bd4, info=(nil)
[canon630u] sane_control_option: handle=0x9204c08, opt=0, act=0, val=0xbfe87ad8, info=(nil)
[canon630u] sane_get_option_descriptor: option = 0
[canon630u] sane_get_option_descriptor: option = 1
[canon630u] sane_get_option_descriptor: option = 2
[canon630u] sane_get_option_descriptor: option = 3
[canon630u] sane_get_option_descriptor: option = 4
[canon630u] sane_get_option_descriptor: option = 5
[canon630u] sane_get_option_descriptor: option = 6
[canon630u] sane_get_option_descriptor: option = 7
[canon630u] sane_control_option: handle=0x9204c08, opt=7, act=0, val=0x8053378, info=(nil)
[canon630u] sane_get_option_descriptor: option = 8
[canon630u] sane_control_option: handle=0x9204c08, opt=8, act=0, val=0x805337c, info=(nil)
[canon630u] sane_control_option: handle=0x9204c08, opt=5, act=0, val=0xbfe87ad4, info=(nil)
[canon630u] sane_control_option: handle=0x9204c08, opt=6, act=0, val=0xbfe87ad4, info=(nil)
[canon630u] sane_control_option: handle=0x9204c08, opt=5, act=0, val=0xbfe87bc8, info=(nil)
[canon630u] sane_get_option_descriptor: option = 7
[canon630u] sane_control_option: handle=0x9204c08, opt=7, act=1, val=0xbfe87bcc, info=0xbfe87ad8
[canon630u] sane_control_option: handle=0x9204c08, opt=6, act=0, val=0xbfe87bc8, info=(nil)
[canon630u] sane_get_option_descriptor: option = 8
[canon630u] sane_control_option: handle=0x9204c08, opt=8, act=1, val=0xbfe87bcc, info=0xbfe87ad8
[canon630u] sane_start
[canon630u] CANON_set_scan_parameters:
[canon630u] cal = 0
[canon630u] gray = 0 (ignored)
[canon630u] res = 75
[canon630u] gain = 1
[canon630u] gamma = 1.599991
[canon630u] in 600dpi pixels:
[canon630u] left = 0, top = 0
[canon630u] right = 5099, bottom = 6999
[canon630u] CANON_start_scan called
[canon630u] init query: 64
[canon630u] init post-reset: 64
[canon630u] Calibrating
[canon630u] seq002 verification error
[canon630u] seq003 verification error
[canon630u] read_poll_flag...
[canon630u] read_poll_flag: timed out (8)
[canon630u] gl640WriteBulk error
[canon630u] Failure on line of canon630u-common.c: 251
[canon630u] gl640WriteBulk error
[canon630u] gl640WriteBulk error
[canon630u] Failure on line of canon630u-common.c: 251
[canon630u] gl640WriteBulk error
[canon630u] gl640WriteBulk error
[canon630u] Failure on line of canon630u-common.c: 251
[canon630u] gl640WriteBulk error
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] waiting...
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] 1 lines, 0 pixels, 6683 extra bytes
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] 1 lines, 0 pixels, 6683 extra bytes
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] waiting...
[canon630u] scan line 0 7k
[canon630u] gl640ReadBulk error
[canon630u] Failure on line of canon630u-common.c: 273
[canon630u] gl640ReadBulk error
[canon630u] 1 lines, 0 pixels, 6683 extra bytes
[canon630u] read_poll_flag...

...

^Cscanimage: received signal 2
scanimage: trying to stop scanner
[canon630u] sane_cancel: handle = 0x9204c08
[canon630u] sane_cancel: cancelling is unsupported in this backend
[canon630u] gl640ReadBulk error
[canon630u] waiting...
[canon630u] scan line 1 7k
^Cscanimage: received signal 2
scanimage: aborting

Two things are interesting here:

1. cancel progresses to line 1
2. another ^C aborts scanimage (why not progress again?)

$ SANE_DEBUG_CANON630U=24 scanimage -T > img.pnm 2> scan.log
(scan.log included)
img.pnm is size 0

Scanner is working fine under Windows and SuSE. So I don't think its a broken scanner.
USB port works fine on any other device, so I don't think its the USB port
Scanner is recognized immediately on plugin, remove detected as well.

It worked in 6.06 and temporarily in 7.10 beta. Never before, never after.

Hope this gives a hint