OpenCL 1.2 AMD-APP (831.4) (available from
http://developer.amd.com/sdks/AMDAPPSDK/Pages/default.aspx ) does NOT see more than one GPU.
You can extract the build number etc. from the library with
$ strings -a /pth/to/the/library.so | grep "^OpenCL.*AMD-APP"
Sorry if this has been mentioned before, but this thread is too long to scan everything.
Not at all. I think you may have discovered the cause of yet another random unexplained failure that has yet to be mentioned on this thread.