Problems With Mining More Than An Hour

I've recently taken up mining. Happens to be Doge at the moment, but that may change once I figure I have enough experience with the way things work. Now on to my problem,

Every time I've left my computer to mine and gone to do whatever else, when I come back there's something wrong. It's usually that cgminer isn't mining anymore and some kind of graphical glitch happening. When I say it's not mining anymore, it's still running but just getting strange errors about declining jobs and others.

I'm running cgminer 3.7.2 using a 270x gpu with this batch file :

setx GPU_MAX_ALLOC_PERCENT 100
setx GPU_USE_SYNC_OBJECTS 1
cgminer.exe --scrypt -o stratum+tcp://teamdoge.com:3333 -u user -p pass --thread-concurrency 26624 -I 16 -g 1 -w 256 --gpu-memclock 1500 --gpu-engine 900 --gpu-fan 85

Of course I'm assuming the graphics card is just crashing and that perhaps it can't restart for some reason. Other times I've had the card crash and restart but cgminer won't start using it again to continue to mine, it'll just sit there doing nothing.

Any advice or answers that you can provide will be appreciated. Also though, is there a full list of config parameters to be used in the batch file? I had found one but it didn't have many of the parameters I had seen in other's configs.

do you have it overclocked? it may be and unstable clock speed/improper voltage for taht speed. I have been mining with another pc w/ a gtx 470 in it and i had it overclocked a bit too high and it would crash the driver, reducing the clock down 25 mhz ands its stable, check to see if that may be happening. and watch any programs you are using to monitor gpu temps/clock speec ect.