I had problems with my ECS K7S5A, both hardware, and software which caused great unstability in Linux. It was mainly due to a faulty ide controler but I ended up returning the board. A friend of mine who got the same board after I advised against it is having the same problems as I had, and with Windows. Also I was unable to get my onboard lan an sound to work on that board while I had it running.
I sent it back and got an MSI K7T Turbo 2 instead and its been great to me. A very stable board, runs 100% in Linux, and I've had no problems yet. So....get an MSI! ;D