Xubuntu 12.04 got frozen after wakeup

[zhanghongce]

I use Xubuntu 12.04 at home, and I have long been troubled by the suspend/resume problem.
I got black screen after resume. If I change to tty1 and type

      sudo pm-suspend

i can got back to the commandline after I type anything on the keyboard to resume. If I stay on tty1 or anywhere except tty7, everything is okay.
If I change to tty7 then system gets frozen.
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Desktop ( not laptop )
Xubuntu 12.04

uname -a:
Linux jia-K8N 3.2.0-67-generic #101-Ubuntu SMP Tue Jul 15 17:46:11 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

lspci :
00:00.0 Host bridge: NVIDIA Corporation nForce3 250Gb Host Bridge (rev a1)
00:01.0 ISA bridge: NVIDIA Corporation nForce3 250Gb LPC Bridge (rev a2)
00:01.1 SMBus: NVIDIA Corporation nForce 250Gb PCI System Management (rev a1)
00:02.0 USB controller: NVIDIA Corporation CK8S USB Controller (rev a1)
00:02.1 USB controller: NVIDIA Corporation CK8S USB Controller (rev a1)
00:02.2 USB controller: NVIDIA Corporation nForce3 EHCI USB 2.0 Controller (rev a2)
00:05.0 Bridge: NVIDIA Corporation CK8S Ethernet Controller (rev a2)
00:06.0 Multimedia audio controller: NVIDIA Corporation nForce3 250Gb AC'97 Audio Controller (rev a1)
00:08.0 IDE interface: NVIDIA Corporation CK8S Parallel ATA Controller (v2.5) (rev a2)
00:0a.0 IDE interface: NVIDIA Corporation nForce3 Serial ATA Controller (rev a2)
00:0b.0 PCI bridge: NVIDIA Corporation nForce3 250Gb AGP Host to PCI Bridge (rev a2)
00:0e.0 PCI bridge: NVIDIA Corporation nForce3 250Gb PCI-to-PCI Bridge (rev a2)
00:18.0 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices, Inc. [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
01:00.0 VGA compatible controller: NVIDIA Corporation NV34 [GeForce FX 5200] (rev a1)

I will attach the file /var/log/pm-suspend.log

I'm guessing whether the problem lies on the video card or not. You see I have a nvidia video card with driver nvidia-173.

Any suggestion on how to locate the problem or any step I can take is appreciated.