Do you use any compression? What pixel format are you saving with? It is a dds file? Is it loaded correctly? Can you display it in a panel or something? What exactly is supposed to be in the texture?

I think that gamestudio uses some directx function to load dds files, which should support many different formats, but the bmap functions only support a small number of formats, so if your texture is really uncompressed, it could be that you can´t really use gamestudios functions to get the pixels, but it should then at least be possible to directly access the texture data.