This usually happens when the image is bigger than the maximum supported texture size (this depends on your graphics card), but it's not supposed to happen for non power of two image dimensions.
Thanks for the swift reply, well, i've looked further into it and it seems it's not to do with the non-power of two images anymore.
The problem is because the sprite sheets can sometimes be very large like 256x8704. I know it's an absurd size, but this is the absolute peak and i got the biggest sheet i could find. I might have to somehow split the image into several manageable chunks maybe.
The problem is, i've had this working with different engines like SDL, ClanLib, XNA and SlimDX and it loaded fine :?