I think I've figured out what is causing it to fail with the 9Ex version. It will require some further investigation but it does seem the likely culprit.
Unfortunately my suspected reason is a change in D3D9Ex itself compared to D3D9.0c, which external plugins accessing the D3D device directly are of course not aware of. As such it will be rather difficult (but hopefully not impossible) to fix. I will look into it further over the weekend.
@WickedX: Oh my, I was not aware that that, as well as some other plugins are available from GitHub now; must be new additions (I downloaded my version about a year ago); awesome, that should help with at least patching those available ones up properly