Okay I am going to help keep this thread alive. In 2006, I had an 11 valve system put in using WM valves and a Hunter C Pro controller. The last 7 years I have replaced selenoid after selenoid after selenoid. At the same time as that installation, I had two additional WM valves put on an existing 6 valve Rainbird system. I have never had any problems with the existing Rainbird vavles or the two new WM valves on the Rainbird system.
I read this post from beginning until the end because I am troubleshooting and open valve. The common theme I saw was that the Hunter C Pro with WM valves had more problems than having a WM Controller or in my case a Rainbird controller.
I was considering changing out each valve but perhaps the controller may be a better route. I do believe I need the updated selenoids as well though since I have been using the generic ones from Lowes. Thoughts anyone?