[deathlessgrasp]

I think it's a game mechanic. The clerical bull's strength will not stack with the arcane either. I don't think any of the ability increasing spells will stack with another of the same effect from a different casting class.

that's because they're spells and not feat based...

moot point I guess now I deleted my bg to be.. no point in playing a class that has been further nerf'd into the ground : /