Filters?

MAGFilter is the filtering method used when the texture is stretched to be larger than it's original size.
MINFilter is the filtering method used when the texture is "squashed" to be smaller than it's size.
MIPFilter is the filtering method used to filter between two levels of MIP maps.

As for the black border, you could try using a Clamp addressing mode for both U and V, but it doesn't really sound like a filtering problem.

'Does anyone know how to remove that little bacl outline that comes along with D3DTSS_MAGFILTER?"

There shouldn't be any black outlines, only might happen if you are doing alpha testing with a badly made texture..