I don't know what's wrong but I downloaded it from you and I do not have a problem. Did you update directx 9.0c November 2008 ?
I don't know why but I downloaded it from you in x64 and the opengl works fine for me before you delete it.The OpenGL plugin needs to be fixed for the x64 builds of Dolphin, it's been broke since around revision 1921 and just crashes the emulator when you try to launch a game.
There is no problem with the DirectX plugin, nor is there a problem with the OpenGL plugin on 32-bit builds of Dolphin, it's just the x64 64-bit build that is broken with OpenGL...
I reported this back when revision 1921 was commited, and it's still not fixed yet...
Sorry if I seem to be a pain, but it makes me think my report is going unnoticed by the developers..