The simple answer that worked for me and probably not the solution you want but - buy an Nvidia card! Seriously though let me give you my two pence.
I have been a ATI fanboy for many years, however after recently trying to upgrade to a 290 and then a 280 (a few different models of both) I have had nothing but problems. The 290 series appears to not to be 100 percent compatible with my Z68 motherboard. The few different 280s that I tried had random crashes / stability issues, errors the same as you describe and a few others. Before anyone says, I tried everything, fresh installs, latest drivers, latest bios ect ect. ( see the various posts I have made)
After reaching the end of my tether, I turned to the 'Green Side' - this is not a decision I took lightly, as I said before I have been an avid ATI fanboy for many years.
Yesterday I took delivery of a Gigabyte GTX 780 Ghz edition, and wow, it just works, the drivers just work, played BF4 last night for a few hours without an issue.
It really was a difficult decision, especially as i always have liked ATI (and with Mantle coming) and it's only been a few hours since i installed the card but I can't help think that Nvidia has much better drivers / stability than ATI and for me made me defect as I had reached the end of my tether.
