Need help. 100% stales. lost 50 shares. [BOUNTY $50 in BTC] [CLAIMED]

[iarsenaux]

I need help. All my hash rate (780kh per card) is going on rejects and stales. It always says on cgminer that i lost shares due to stratum disconnect. I am mining at middlecoin.com

Mobo: msi z87 g65
Cpu: i5 3.1ghz
Gpu: r9 280x dc2 top v1
Os : win 8 pro
Ram: 8gb
Drivers: amd cata 13.12 , sdk 2.7
Cgminer 3.3.1

Memclock: 1800
Engine : 1120
Vddc : stock
i : 13    Concurrency: 8192