btw, removing the flag doesn't do anything after adding it, how does this work? Do I have to press enter everytime i type something in the gui?
You have to stop the miner and start it again if you type a new flag.
so, what else do i have to change? it's running stock.
Downclock the GPU memory to 300 or less
is radeon 5830/5850 still the best bang for the buck?
Popular mining cards :https://en.bitcoin.it/wiki/Mining_hardware_comparison#Popular_Mining_Cards
Look at MH/$ and MH/J. The higher, the better.