Screen does not shutdown in lock screen; displays stripes

[Perfi]

Hi! I'm new to Mint. Loving it so far, but I've found something that may be a bug which I have not been able to solve by googling.

My lock screen looks like this: http://imgur.com/UV9bxee,t155nZl. Completely fine. But after I leave it for some time, I come back to this: http://imgur.com/UV9bxee,t155nZl#1 whereas I would expect the screen to shut down. The weird striped display goes away as I move the mouse to go back to the lock screen and enter my password.

What's worse, I think this might be damaging my screen as there is a difference in displayed graphics between the white and striped areas upon coming back to normality. It's hard to describe the effect, the display at at the previously white area seems darker, as if there had been strain on the screen in that region. After some time, the graphics return to normality.

I've been browsing for a while now and haven't been able to find any solutions.

I run the cinnamon desktop. I'm not sure if this is the appropriate subforum to post this, but I was kind of at a loss as for picking one.

Here's my inxi -Fxz output:

Code: Select all

System:    Host: Dominik-PC Kernel: 3.13.0-37-generic x86_64 (64 bit, gcc: 4.8.2) 
           Desktop: Gnome Distro: Linux Mint 17.1 Rebecca
Machine:   Mobo: Gigabyte model: G31MX-S2 version: x.x Bios: Award version: F5i date: 12/16/2008
CPU:       Quad core Intel Core2 Quad CPU Q6600 (-MCP-) cache: 4096 KB flags: (lm nx sse sse2 sse3 ssse3 vmx) bmips: 23977.3 
           Clock Speeds: 1: 2000.00 MHz 2: 2000.00 MHz 3: 2000.00 MHz 4: 2000.00 MHz
Graphics:  Card: NVIDIA GF114 [GeForce GTX 560 Ti] bus-ID: 01:00.0 
           X.Org: 1.15.1 drivers: nvidia (unloaded: fbdev,vesa,nouveau) Resolution: 1680x1050@60.0hz 
           GLX Renderer: GeForce GTX 560 Ti/PCIe/SSE2 GLX Version: 4.4.0 NVIDIA 331.113 Direct Rendering: Yes
Audio:     Card-1: Intel NM10/ICH7 Family High Definition Audio Controller driver: snd_hda_intel bus-ID: 00:1b.0
           Card-2: NVIDIA GF114 HDMI Audio Controller driver: snd_hda_intel bus-ID: 01:00.1
           Card-3: Microsoft LifeCam VX-3000 driver: USB Audio usb-ID: 045e:00f5
           Sound: Advanced Linux Sound Architecture ver: k3.13.0-37-generic
Network:   Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller 
           driver: r8169 ver: 2.3LK-NAPI port: d000 bus-ID: 02:00.0
           IF: eth0 state: up speed: 100 Mbps duplex: full mac: <filter>
Drives:    HDD Total Size: 320.1GB (68.0% used) 1: id: /dev/sda model: SAMSUNG_HD321KJ size: 320.1GB 
Partition: ID: / size: 38G used: 8.1G (23%) fs: ext4 ID: swap-1 size: 4.29GB used: 0.00GB (0%) fs: swap 
RAID:      No RAID devices detected - /proc/mdstat and md_mod kernel raid module present
Sensors:   System Temperatures: cpu: 56.0C mobo: N/A gpu: 0.0:44C 
           Fan Speeds (in rpm): cpu: N/A 
Info:      Processes: 162 Uptime: 1:58 Memory: 1431.8/3952.1MB Runlevel: 2 Gcc sys: 4.8.2 Client: Shell inxi: 1.8.4 

[DrHu]

Graphics: Card: NVIDIA GF114 [GeForce GTX 560 Ti] bus-ID: 01:00.0
X.Org: 1.15.1 drivers: nvidia (unloaded: fbdev,vesa,nouveau) Resolution: 1680x1050@60.0hz
GLX Renderer: GeForce GTX 560 Ti/PCIe/SSE2 GLX Version: 4.4.0 NVIDIA 331.113 Direct Rendering: Yes

So, you display is supposedly in landscape mode at 1680x1050
1050 is of course an odd resolution, since 1280 or 1024 would be more likely as an HD display

Ubuntu NVIDIA iINFO
http://askubuntu.com/questions/451221/u ... dia-driver

OK, the first thing I see the screen has switched to a portait mode(vertical ) and doesn't fill the screen across (landscape)
Since it happens after a time; that suggests powwer control for that monitor
--check settings for monitor/display and any screen savers you have schedules as well as power control (turn off monitor after 20mins as an example)

So it may have more to do with your particular device than the Linux desktop management
--being oddly controlled in some manner (by itself)