Am experiencing the same problems since the update I did today. Am attaching some dmesg output (it says something about "bug" together with ACPI so I am guessing it might be useful):
[ 28.232000] input: Power Button (FF) as /class/input/input4 [ 28.260000] ACPI: Power Button (FF) [PWRF] [ 28.328000] input: Lid Switch as /class/input/input5 [ 28.360000] ACPI: Lid Switch [LID] [ 28.424000] input: Sleep Button (CM) as /class/input/input6 [ 28.424000] ACPI: Sleep Button (CM) [SLPB] [ 28.476000] Using specific hotkey driver [ 28.592000] No dock devices found. [ 28.720000] BUG: at lib/kref.c:32 kref_get() [ 28.720000] [<c01ee21d>] kref_get+0x3d/0x40 [ 28.720000] [<c01ed50f>] kobject_get+0xf/0x20 [ 28.720000] [<c025515e>] get_device+0xe/0x20 [ 28.720000] [<c0255768>] device_add+0x78/0x530 [ 28.720000] [<c01ed50f>] kobject_get+0xf/0x20 [ 28.720000] [<c01ed92b>] kobject_init+0x2b/0x40 [ 28.720000] [<e0d2460b>] i2c_add_adapter+0x12b/0x280 [i2c_core] [ 28.720000] [<e0d1b573>] acpi_ec_hc_add+0x122/0x16b [i2c_ec] [ 28.720000] [<c02ecd1a>] cond_resched+0x2a/0x40 [ 28.720000] [<c0228a3d>] acpi_bus_driver_init+0x28/0x4b [ 28.720000] [<c0229ad8>] acpi_bus_register_driver+0x82/0xb7 [ 28.720000] [<e0a5c00a>] acpi_ec_hc_init+0xa/0x11 [i2c_ec] [ 28.720000] [<c014416d>] sys_init_module+0x15d/0x1ba0 [ 28.720000] [<c0107a5d>] sys_mmap2+0xcd/0xd0 [ 28.720000] [<c01031f0>] sysenter_past_esp+0x69/0xa9 [ 28.720000] ======================= [ 28.720000] BUG: unable to handle kernel NULL pointer dereference at virtual address 0000000c [ 28.720000] printing eip: [ 28.720000] c01b7f4d [ 28.720000] *pde = 00000000 [ 28.720000] Oops: 0000 [#1] [ 28.720000] SMP [ 28.720000] Modules linked in: i2c_ec i2c_core dock button battery container ac asus_acpi backlight nls_iso8859_1 nls_cp437 vfat fat ipv6 fuse sbp2 parport_pc lp parport snd_intel8x0 snd_ac97_codec pcmcia ac97_bus snd_pcm_oss snd_mixer_oss snd_pcm snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi joydev ipw2200 tifm_7xx1 tifm_core ieee80211 ieee80211_crypt yenta_socket rsrc_nonstatic pcmcia_core snd_seq_midi_event snd_seq snd_timer snd_seq_device irda crc_ccitt snd soundcore snd_page_alloc psmouse serio_raw shpchp intel_agp agpgart pci_hotplug iTCO_wdt iTCO_vendor_support af_packet tsdev evdev ext3 jbd mbcache sg usbhid hid sr_mod cdrom sd_mod ata_piix ata_generic libata scsi_mod ohci1394 ieee1394 b44 mii generic ehci_hcd uhci_hcd usbcore thermal processor fan fbcon tileblit font bitblit softcursor vesafb capability commoncap [ 28.720000] CPU: 0 [ 28.720000] EIP: 0060:[<c01b7f4d>] Not tainted VLI [ 28.720000] EFLAGS: 00010292 (2.6.20-13-generic #2) [ 28.720000] EIP is at create_dir+0x1d/0x1e0 [ 28.720000] eax: d6f73cc0 ebx: d6f73cc4 ecx: d6f73cc4 edx: 00000000 [ 28.720000] esi: d6f73cc0 edi: d6f73cc4 ebp: 00000000 esp: de639dc8 [ 28.720000] ds: 007b es: 007b ss: 0068 [ 28.720000] Process modprobe (pid: 4410, ti=de638000 task=de41a560 task.ti=de638000) [ 28.720000] Stack: c0126b6b 00000014 00000000 d6f73cc0 d6f73cc4 d6f73d06 00000000 c01b884c [ 28.720000] de639dec 00000000 d6f73cc0 c01ed7ba d6f73cc0 c01edac7 de639e2c 00000020 [ 28.720000] de50aec0 d6f73c48 d6f73d00 d6f73d06 de50ae48 c02557a7 d6f73cc0 c0362eee [ 28.720000] Call Trace: [ 28.720000] [<c0126b6b>] printk+0x1b/0x20 [ 28.720000] [<c01b884c>] sysfs_create_dir+0x2c/0x70 [ 28.720000] [<c01ed7ba>] kobject_add+0x8a/0x1a0 [ 28.720000] [<c01edac7>] kobject_set_name+0x37/0xb0 [ 28.720000] [<c02557a7>] device_add+0xb7/0x530 [ 28.720000] [<c01ed50f>] kobject_get+0xf/0x20 [ 28.720000] [<c01ed92b>] kobject_init+0x2b/0x40 [ 28.720000] [<e0d2460b>] i2c_add_adapter+0x12b/0x280 [i2c_core] [ 28.720000] [<e0d1b573>] acpi_ec_hc_add+0x122/0x16b [i2c_ec] [ 28.720000] [<c02ecd1a>] cond_resched+0x2a/0x40 [ 28.720000] [<c0228a3d>] acpi_bus_driver_init+0x28/0x4b [ 28.720000] [<c0229ad8>] acpi_bus_register_driver+0x82/0xb7 [ 28.720000] [<e0a5c00a>] acpi_ec_hc_init+0xa/0x11 [i2c_ec] [ 28.720000] [<c014416d>] sys_init_module+0x15d/0x1ba0 [ 28.720000] [<c0107a5d>] sys_mmap2+0xcd/0xd0 [ 28.720000] [<c01031f0>] sysenter_past_esp+0x69/0xa9 [ 28.720000] ======================= [ 28.720000] Code: f6 ff e8 67 d0 f4 ff eb b6 90 8d 74 26 00 83 ec 1c 89 5c 24 0c 89 cb 89 74 24 10 89 c6 89 7c 24 14 89 df 89 6c 24 18 89 54 24 08 <8b> 42 0c 83 c0 70 e8 c8 58 13 00 31 c0 b9 ff ff ff ff f2 ae f7 [ 28.720000] EIP: [<c01b7f4d>] create_dir+0x1d/0x1e0 SS:ESP 0068:de639dc8 [ 28.720000] <3>ibm_acpi: ec object not found -- Feisty stops booting at "Loading ACPI modules" https://launchpad.net/bugs/97065 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
