I am having the exact same problem as the one mentioned here viewtopic.php?f=9&p=10510#p4123
. That is, GPU mining does not start (turns green for a few seconds, displays last hashrate static, turns black). It seemed to work for the first 5 minutes after first installing the software, though. I tried to mess about with the intensity and core use to see if there was a connection, which sort of worked but eventually it refused to function so I am at a loss.
GPU: Radeon R9 280x
v.6.6, which works on my other pc with nvidia and android