Description of problem:
This seems to happen quite randomly, within five minutes of the machine booting up. It's either the machine works fine for the whole day, or it just goes down, and me powering off the machine and turning it back on.

Additional info:
libreport version: 2.0.18
abrt_version:   2.0.18
cmdline:        BOOT_IMAGE=/vmlinuz-3.6.7-4.fc17.i686 root=UUID=acd270ae-2601-4c80-a875-2b123b7d9333 ro rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=True KEYTABLE=us rd.luks=0 LANG=en_US.UTF-8 rhgb quiet
kernel:         3.6.7-4.fc17.i686

backtrace:
:BUG: unable to handle kernel paging request at 0200003c
:IP: [<c0598a73>] pde_put+0x13/0x80
:*pde = 00000000 
:Oops: 0002 [#1] SMP 
:Modules linked in: fuse bnep bluetooth ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables nf_conntrack_ipv4 nf_defrag_ipv4 xt_state nf_conntrack binfmt_misc snd_hda_codec_analog iTCO_wdt iTCO_vendor_support snd_hda_intel snd_hda_codec snd_hwdep snd_seq snd_seq_device snd_pcm arc4 thinkpad_acpi iwl3945 iwlegacy mac80211 coretemp snd_page_alloc cfg80211 rfkill e1000e snd_timer snd soundcore lpc_ich i2c_i801 microcode uinput firewire_ohci firewire_core crc_itu_t yenta_socket wmi i915 video i2c_algo_bit drm_kms_helper drm i2c_core
:Pid: 1236, comm: pool Not tainted 3.6.7-4.fc17.i686 #1 LENOVO 7732CTO/7732CTO
:EIP: 0060:[<c0598a73>] EFLAGS: 00210286 CPU: 0
:EIP is at pde_put+0x13/0x80
:EAX: 02000000 EBX: 02000000 ECX: 00000000 EDX: eb87f800
:ESI: f03cb92c EDI: c096f040 EBP: eb8cbe08 ESP: eb8cbe00
: DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
:CR0: 8005003b CR2: 0200003c CR3: 2b8ae000 CR4: 000007d0
:DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
:DR6: ffff0ff0 DR7: 00000400
:Process pool (pid: 1236, ti=eb8ca000 task=f0ba7110 task.ti=eb8ca000)
:Stack:
: f03cb890 f03cb92c eb8cbe14 c0592e05 f03cb890 eb8cbe28 c055a268 f03cb890
: f03cb8e4 f4435000 eb8cbe40 c055a3f1 eacb37e8 eacb3780 f03cb890 eacb3700
: eb8cbe60 c0556ea7 c0555ced eacb3780 eb8cbeac eacb37e0 eb8cbeac f03cb890
:Call Trace:
: [<c0592e05>] proc_evict_inode+0x35/0x60
: [<c055a268>] evict+0x88/0x150
: [<c055a3f1>] iput+0xc1/0x190
: [<c0556ea7>] d_kill+0xa7/0xf0
: [<c0555ced>] ? __dentry_lru_del+0x1d/0x50
: [<c0556fb4>] shrink_dentry_list+0xc4/0x1b0
: [<c0557236>] shrink_dcache_parent+0x196/0x210
: [<c0597b28>] proc_flush_task+0x138/0x1b0
: [<c04e7110>] ? remote_function+0x40/0x40
: [<c04407e4>] release_task+0x24/0x420
: [<c046147d>] ? switch_task_namespaces+0x1d/0x50
: [<c0442397>] do_exit+0x477/0x800
: [<c0487367>] ? getnstimeofday+0x47/0x130
: [<c0442978>] sys_exit+0x18/0x20
: [<c0955304>] syscall_call+0x7/0xb
: [<c0950000>] ? ec_install_handlers+0x8f/0x99
:Code: 80 43 50 01 be fb ff ff ff eb c8 8d b6 00 00 00 00 8d bc 27 00 00 00 00 55 89 e5 83 ec 08 89 5d f8 89 75 fc 66 66 66 66 90 89 c3 <f0> ff 48 3c 0f 94 c0 84 c0 75 0a 8b 5d f8 8b 75 fc 89 ec 5d c3
:EIP: [<c0598a73>] pde_put+0x13/0x80 SS:ESP 0068:eb8cbe00
:CR2: 000000000200003c