You're right Bubba, I'm sorry for my poor choice of words. I meant to say its not clearing the window...not the vertex buffer :P
I also found that if I construct the method like so:
The function will return an "S_OK", and will clear properly for textures being drawn.
HRESULT a = pDevice->Clear(0, 0, D3DCLEAR_TARGET, 0, 1.0f, 0);
However, the following code, when drawing the vertices OR the textures, will return -2005530516:
HRESULT a = pDevice->Clear(0, 0, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, 0, 1.0f, 0);
It appears that for some reason, whenever I combine the flags, the method fails. Does anyone know of any possible reason for this?