Help with Overclocking Athlon 2 620 x4

Hey guys! I banging my head against a brick wall here as I have no idea how to get around it!
I've been googling around and read almost every topic about overclocking this processor but still can't get it past 3.1  
Alot of people have been able to get it to 3.25 and even 3.5 without facing any issues whatsoever  

I don't know what the best way about going about this so.. I'll just upload some snaps' of my BIOS:
http://img96.imageshack.us/img96/5255/20120629220443.jp...
http://img194.imageshack.us/img194/8373/20120629220458....
http://img835.imageshack.us/img835/8846/20120629220509....
http://img3.imageshack.us/img3/598/20120629220524.jpg
http://img804.imageshack.us/img804/4880/20120629220535....

Thanks for any help you can give here. I know it's an older processor now (I'll probably be splashing out for a 2500k sooner rather than later) but I could really use the extra power (Starcraft 2 seems to be getting more demanding after every patch)