Here a Oops from a computer at startup:

Dec 19 06:08:44 mars kernel: [   20.086200] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000038
Dec 19 06:08:44 mars kernel: [   20.086205]  printing eip:
Dec 19 06:08:44 mars kernel: [   20.086207] f8d03bb6
Dec 19 06:08:44 mars kernel: [   20.086208] *pde = 00000000
Dec 19 06:08:44 mars kernel: [   20.086211] Oops: 0000 [#1]
Dec 19 06:08:44 mars kernel: [   20.086212] SMP 
Dec 19 06:08:44 mars kernel: [   20.086215] Modules linked in: nfs lockd sunrpc nls_utf8 ntfs nls_iso8859_1 nls_cp437 vfat fat it87 hwmon_vid i2c_isa eeprom i2c_i801 parport_pc lp parport fuse snd_ice1724 snd_ice17xx_ak4xxx snd_ac97_codec ac97_bus af_packet snd_ak4114 snd_pcm_oss snd_mixer_oss snd_pcm snd_page_alloc snd_ak4xxx_adda snd_mpu401_uart snd_seq_dummy snd_seq_oss snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer xpad sky2 nvidia(P) snd_seq_device snd i2c_core soundcore intel_agp iTCO_wdt iTCO_vendor_support agpgart shpchp pci_hotplug psmouse serio_raw pcspkr tsdev evdev ext3 jbd mbcache sg sr_mod sd_mod cdrom generic usbhid hid ata_piix pata_jmicron usb_storage libusual ahci ata_generic via_rhine mii libata floppy scsi_mod uhci_hcd ehci_hcd usbcore thermal processor fan fbcon tileblit font bitblit softcursor vesafb capability commoncap
Dec 19 06:08:44 mars kernel: [   20.086280] CPU:    0
Dec 19 06:08:44 mars kernel: [   20.086281] EIP:    0060:[<f8d03bb6>]    Tainted: P      VLI
Dec 19 06:08:44 mars kernel: [   20.086282] EFLAGS: 00010206   (2.6.20-16-generic #2)
Dec 19 06:08:44 mars kernel: [   20.086293] EIP is at nfs_fhget+0xc6/0x3d0 [nfs]
Dec 19 06:08:44 mars kernel: [   20.086295] eax: 00000000   ebx: 00000000   ecx: dfc15a74   edx: 00004180
Dec 19 06:08:44 mars kernel: [   20.086297] esi: dfc15a00   edi: f504fbd8   ebp: f6653da0   esp: f504fb90
Dec 19 06:08:44 mars kernel: [   20.086299] ds: 007b   es: 007b   ss: 0068
Dec 19 06:08:44 mars kernel: [   20.086301] Process mount (pid: 4823, ti=f504e000 task=df8a5030 task.ti=f504e000)
Dec 19 06:08:44 mars kernel: [   20.086302] Stack: f8d03a90 f504fbb0 c200ce34 c200ce34 00000000 f6653c78 00000080 00000080 
Dec 19 06:08:44 mars kernel: [   20.086307]        f504fc6a f504fbd8 f504fbd8 dfc15a00 f504fc68 f504fd22 f8d024b7 00000000 
Dec 19 06:08:44 mars kernel: [   20.086312]        00000000 dfc15800 00000002 00000000 00000000 00000000 00000000 00000000 
Dec 19 06:08:44 mars kernel: [   20.086316] Call Trace:
Dec 19 06:08:44 mars kernel: [   20.086320]  [<f8d03a90>] nfs_init_locked+0x0/0x60 [nfs]
Dec 19 06:08:44 mars kernel: [   20.086339]  [<f8d024b7>] nfs4_get_root+0x177/0x260 [nfs]
Dec 19 06:08:44 mars kernel: [   20.086371]  [<f8d059bd>] nfs4_get_sb+0x28d/0x350 [nfs]
Dec 19 06:08:44 mars kernel: [   20.086398]  [vfs_kern_mount+182/304] vfs_kern_mount+0xb6/0x130
Dec 19 06:08:44 mars kernel: [   20.086405]  [do_kern_mount+57/96] do_kern_mount+0x39/0x60
Dec 19 06:08:44 mars kernel: [   20.086409]  [do_mount+762/1808] do_mount+0x2fa/0x710
Dec 19 06:08:44 mars kernel: [   20.086415]  [ip_rcv+700/1280] ip_rcv+0x2bc/0x500
Dec 19 06:08:44 mars kernel: [   20.086420]  [<f8af42ca>] packet_rcv_spkt+0x10a/0x1b0 [af_packet]
Dec 19 06:08:44 mars kernel: [   20.086426]  [inet_sock_destruct+186/496] inet_sock_destruct+0xba/0x1f0
Dec 19 06:08:44 mars kernel: [   20.086430]  [show_scaling_max_freq+24/32] show_scaling_max_freq+0x18/0x20
Dec 19 06:08:44 mars kernel: [   20.086435]  [sk_free+128/240] sk_free+0x80/0xf0
Dec 19 06:08:44 mars kernel: [   20.086438]  [<f88a446a>] rhine_interrupt+0x69a/0xb80 [via_rhine]
Dec 19 06:08:44 mars kernel: [   20.086444]  [__kfree_skb+74/288] __kfree_skb+0x4a/0x120
Dec 19 06:08:44 mars kernel: [   20.086454]  [common_interrupt+35/48] common_interrupt+0x23/0x30
Dec 19 06:08:44 mars kernel: [   20.086461]  [copy_mount_options+64/336] copy_mount_options+0x40/0x150
Dec 19 06:08:44 mars kernel: [   20.086466]  [sys_mount+119/192] sys_mount+0x77/0xc0
Dec 19 06:08:44 mars kernel: [   20.086471]  [sysenter_past_esp+105/169] sysenter_past_esp+0x69/0xa9
Dec 19 06:08:44 mars kernel: [   20.086478]  =======================
Dec 19 06:08:44 mars kernel: [   20.086479] Code: 00 00 8d 80 d8 fe ff ff 89 44 24 14 81 8d 3c 01 00 00 82 00 00 00 89 5d 20 8b 57 20 66 89 55 6a 8b 86 60 01 00 00 0f b7 d2 8b 00 <8b> 40 38 8b 40 0c 89 85 90 00 00 00 89 d0 25 00 f0 00 00 3d 00 
Dec 19 06:08:44 mars kernel: [   20.086501] EIP: [<f8d03bb6>] nfs_fhget+0xc6/0x3d0 [nfs] SS:ESP 0068:f504fb90