12.04 - System crashes (screen doesn't get updated) when playing 'heavy' videogames

apparently my system is crashing (i.e. the screen is frozen, but I can connect via ssh - kill -9 -1 doesn't kill all my processes though) when I play intensive videogames/3D benchmarks (SC2, HoN and the Unigine Valley benchmark).

What I've experienced so far is that apparently the GPU (nVidia 470 GTX) skyrockets to 91+ degree of temperature.
If I keep the case open this behaviour usually doesn't happen.

What do you think it is? Is it my GPU bruned and doesn't tolerate high temperatures anymore?

I'm using Ubuntu 12.04 (x86-64) and driver nVidia 310.14.

Cheers

Looks like it's a bug triggered in nVidia driver (looking in /var/log/kern.log):

Aug  9 07:27:25 scv kernel: [  420.064006] BUG: soft lockup - CPU#0 stuck for 23s! [valley_x64:3006]
Aug  9 07:27:25 scv kernel: [  420.064008] Modules linked in: dm_crypt pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) parport_pc ppdev rfcomm bnep bluetooth binfmt_misc ext2 snd_hda_codec_hdmi snd_hda_codec_realtek arc4 uvcvideo videodev v4l2_compat_ioctl32 snd_virtuoso snd_oxygen_lib snd_mpu401_uart psmouse snd_seq_midi snd_seq_midi_event ath9k snd_seq snd_hda_intel snd_hda_codec sp5100_tco snd_hwdep i2c_piix4 mac80211 snd_rawmidi asus_atk0110 snd_pcm k10temp ath9k_common serio_raw ath9k_hw ath nvidia(P) edac_core edac_mce_amd cfg80211 snd_timer snd_seq_device snd soundcore snd_page_alloc mac_hid wmi lp parport usbhid hid pata_atiixp r8169 firewire_ohci firewire_core crc_itu_t pata_via
Aug  9 07:27:25 scv kernel: [  420.064044] CPU 0
Aug  9 07:27:25 scv kernel: [  420.064045] Modules linked in: dm_crypt pci_stub vboxpci(O) vboxnetadp(O) vboxnetflt(O) vboxdrv(O) parport_pc ppdev rfcomm bnep bluetooth binfmt_misc ext2 snd_hda_codec_hdmi snd_hda_codec_realtek arc4 uvcvideo videodev v4l2_compat_ioctl32 snd_virtuoso snd_oxygen_lib snd_mpu401_uart psmouse snd_seq_midi snd_seq_midi_event ath9k snd_seq snd_hda_intel snd_hda_codec sp5100_tco snd_hwdep i2c_piix4 mac80211 snd_rawmidi asus_atk0110 snd_pcm k10temp ath9k_common serio_raw ath9k_hw ath nvidia(P) edac_core edac_mce_amd cfg80211 snd_timer snd_seq_device snd soundcore snd_page_alloc mac_hid wmi lp parport usbhid hid pata_atiixp r8169 firewire_ohci firewire_core crc_itu_t pata_via
Aug  9 07:27:25 scv kernel: [  420.064066]
Aug  9 07:27:25 scv kernel: [  420.064068] Pid: 3006, comm: valley_x64 Tainted: P           O 3.2.0-51-generic #77-Ubuntu System manufacturer System Product Name/M4A88TD-V EVO/USB3
Aug  9 07:27:25 scv kernel: [  420.064072] RIP: 0010:[]  [] _nv003210rm+0x47ff/0xaf83 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064186] RSP: 0018:ffff8801d068bbf8  EFLAGS: 00000296
Aug  9 07:27:25 scv kernel: [  420.064188] RAX: 0000000000000045 RBX: 0000000000070004 RCX: 0000000000000008
Aug  9 07:27:25 scv kernel: [  420.064189] RDX: 0000000000070004 RSI: 0000000000000000 RDI: ffff88020f0d0008
Aug  9 07:27:25 scv kernel: [  420.064191] RBP: ffff8801f355ae78 R08: 0000000000070004 R09: ffff8801f355aea0
Aug  9 07:27:25 scv kernel: [  420.064192] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
Aug  9 07:27:25 scv kernel: [  420.064193] R13: 0000000000000246 R14: 0000000000000000 R15: ffff8801f355ae80
Aug  9 07:27:25 scv kernel: [  420.064195] FS:  00007f38536a1740(0000) GS:ffff88022fc00000(0000) knlGS:0000000000000000
Aug  9 07:27:25 scv kernel: [  420.064196] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Aug  9 07:27:25 scv kernel: [  420.064198] CR2: 00007f383abe46b0 CR3: 000000020755d000 CR4: 00000000000006f0
Aug  9 07:27:25 scv kernel: [  420.064199] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
Aug  9 07:27:25 scv kernel: [  420.064201] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Aug  9 07:27:25 scv kernel: [  420.064202] Process valley_x64 (pid: 3006, threadinfo ffff8801d068a000, task ffff88021d5a1700)
Aug  9 07:27:25 scv kernel: [  420.064204] Stack:
Aug  9 07:27:25 scv kernel: [  420.064208]  ffff88020f0d0008 0000000000000045 ffff88020f0d0008 0000000000070004
Aug  9 07:27:25 scv kernel: [  420.064212]  0000000000000003 ffffffffa037e450 0000000000000001 0000000000000001
Aug  9 07:27:25 scv kernel: [  420.064214]  ffff88020f0d0008 ffff88020c7f4008 00000000beef0003 ffffffffa037e63d
Aug  9 07:27:25 scv kernel: [  420.064216] Call Trace:
Aug  9 07:27:25 scv kernel: [  420.064287]  [] ? _nv005265rm+0x116/0x1b9 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064353]  [] ? _nv005084rm+0x14a/0x1ed [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064407]  [] ? _nv010822rm+0x127/0x1cb [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064461]  [] ? _nv010828rm+0xec/0x111 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064495]  [] ? _nv000771rm+0x28ca/0x2b89 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064530]  [] ? _nv000738rm+0xe23/0xe59 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064564]  [] ? _nv000771rm+0x73/0x2b89 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064598]  [] ? _nv000697rm+0x26/0x147 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064633]  [] ? _nv000803rm+0x2dd/0xa05 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064667]  [] ? rm_ioctl+0x76/0x100 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064702]  [] ? nv_kern_ioctl+0x15e/0x490 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064735]  [] ? nv_kern_unlocked_ioctl+0x21/0x30 [nvidia]
Aug  9 07:27:25 scv kernel: [  420.064739]  [] ? do_vfs_ioctl+0x8a/0x340
Aug  9 07:27:25 scv kernel: [  420.064742]  [] ? do_munmap+0x1f3/0x2f0
Aug  9 07:27:25 scv kernel: [  420.064744]  [] ? sys_ioctl+0x91/0xa0
Aug  9 07:27:25 scv kernel: [  420.064747]  [] ? system_call_fastpath+0x16/0x1b

I'm trying nVidia drivers version 304.88 and so far seems fine...