I am fighting with a USB CDRW drive that does not quite work, and while unpluging it
while it didn't want to be unmounted, I got:

May 26 16:35:33 prony kernel: ehci_hcd 0000:00:10.4: GetStatus port 1 status 003802 POWER OWNER sig=j  CSC
May 26 16:35:33 prony kernel: hub 1-0:1.0: port 1, status 0, change 1, 12 Mb/s
May 26 16:35:33 prony kernel: ehci_hcd 0000:00:10.4: GetStatus port 2 status 001002 POWER sig=se0  CSC
May 26 16:35:33 prony kernel: hub 1-0:1.0: port 2, status 100, change 1, 12 Mb/s
May 26 16:35:33 prony kernel: usb 1-2: USB disconnect, address 4
May 26 16:35:33 prony kernel: usb 1-2: usb_disable_device nuking all URBs
May 26 16:35:33 prony kernel: usb 1-2: unregistering interface 1-2:1.0
May 26 16:35:33 prony kernel: usb-storage: storage_disconnect() called
May 26 16:35:33 prony kernel: usb-storage: usb_stor_stop_transport called
May 26 16:35:33 prony kernel: usb-storage: -- dissociate_dev
May 26 16:35:33 prony kernel: usb-storage: -- sending exit command to thread
May 26 16:35:33 prony kernel: ----------- [cut here ] --------- [please bite here ] ---------
May 26 16:35:33 prony kernel: Kernel BUG at usb:848
May 26 16:35:33 prony kernel: invalid operand: 0000 [1] SMP
May 26 16:35:33 prony kernel: CPU 0
May 26 16:35:33 prony kernel: Pid: 6, comm: khubd Not tainted 2.6.6
May 26 16:35:33 prony kernel: RIP: 0010:[<ffffffff803d5aa3>] <ffffffff803d5aa3>{usb_stor_release_resources+83}
May 26 16:35:33 prony kernel: RSP: 0000:000001003fc9bda8  EFLAGS: 00010202
May 26 16:35:33 prony kernel: RAX: 0000000000000032 RBX: 000001003c654800 RCX: 0000000000000000
May 26 16:35:33 prony kernel: RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000100000000
May 26 16:35:33 prony kernel: RBP: 000001003f419c00 R08: 0000000000000000 R09: 0000000000000202
May 26 16:35:33 prony kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff80607a60
May 26 16:35:33 prony kernel: R13: 000001003de01188 R14: 000001003de01188 R15: 000001003faab600
May 26 16:35:33 prony kernel: FS:  0000000000000000(0000) GS:ffffffff806f5480(0000) knlGS:0000000000000000
May 26 16:35:33 prony kernel: CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
May 26 16:35:33 prony kernel: CR2: 0000000055569000 CR3: 0000000000101000 CR4: 00000000000006e0
May 26 16:35:33 prony kernel: Process khubd (pid: 6, stackpage=10001e73080)
May 26 16:35:33 prony kernel: Stack: ffffffff80607a20 ffffffff803b8c3b 000001003f419c18 ffffffff80607a60
May 26 16:35:33 prony kernel:        000001003f419c00 ffffffff803325d3 000001003f419c18 000001003f419c18
May 26 16:35:33 prony kernel:        000001003de010f0 ffffffff803326fb
May 26 16:35:33 prony kernel: Call Trace:<ffffffff803b8c3b>{usb_unbind_interface+59} <ffffffff803325d3>{device_release_driver+83}
May 26 16:35:33 prony kernel:        <ffffffff803326fb>{bus_remove_device+59} <ffffffff803316e8>{device_del+88}
May 26 16:35:33 prony kernel:        <ffffffff80331729>{device_unregister+9} <ffffffff803bff35>{usb_disable_device+213}
May 26 16:35:33 prony kernel:        <ffffffff803b9942>{usb_disconnect+210} <ffffffff803bc11e>{hub_port_connect_change+190}
May 26 16:35:33 prony kernel:        <ffffffff803bc53e>{hub_events+510} <ffffffff803bc785>{hub_thread+37}
May 26 16:35:33 prony kernel:        <ffffffff80133f30>{default_wake_function+0} <ffffffff801116ef>{child_rip+8}
May 26 16:35:33 prony kernel:        <ffffffff803bc760>{hub_thread+0} <ffffffff801116e7>{child_rip+0}
May 26 16:35:33 prony kernel:
May 26 16:35:33 prony kernel:
May 26 16:35:33 prony kernel: Code: 0f 0b dc d2 52 80 ff ff ff ff 50 03 90 48 c7 83 f0 00 00 00
May 26 16:35:33 prony kernel: RIP <ffffffff803d5aa3>{usb_stor_release_resources+83} RSP <000001003fc9bda8>
May 26 16:35:33 prony kernel:  <3>scsi9 (0:0): rejecting I/O to dead device
May 26 16:35:33 prony kernel: sr1: CDROM (ioctl) error, command: Xpwrite, Read disk info 00 00 00 00 00 00 00 02 00
May 26 16:35:33 prony kernel: sr: old sense key No Sense
May 26 16:35:33 prony kernel: Non-extended sense class 0 code 0x0
May 26 16:35:37 prony kernel: usb-storage: Reset interrupted by disconnect
May 26 16:35:37 prony kernel: usb-storage: scsi cmd done, result=0x70000
May 26 16:35:37 prony kernel: usb-storage: *** thread sleeping.

Do you need anything else, besides the attached gunziped config.gz?

Yours, Florian.