for the 5800 series cards try -v -w128 fellas...

my 5850 does ~350 MH/s at 935MHz/345MHz and with the fan at 60% it stays around 60°...

also use MSIafterburner to overclock and underclock...

1. your unofficialoverclocking lines in MSIafterburner.cfg should read like this if you want to OC/UC...

UnofficialOverclockingEULA   = I confirm that I am aware of unofficial overclocking limitations and fully understand that MSI will not provide me any support on it
UnofficialOverclockingMode   = 1

2. to underclock your memory go into CCC and set the card defaults in CCC Overdrive, close CCC, then open MSIafterburner, set your core clock, and then slide the memory all the way down as low as it will go, apply and then exit, open afterburner up AGAIN and your mem clocks should be able to go lower than was listed before...