Sorry, but my english isn't good

I have TV3D v6.5.
I do something like that:
-- creating memory stream
-- saving bitmap to this memory stream
-- loading BMP from memory with LoadTexture
-- modifying bitmap [but not changing size]
-- saving to memory stream
-- loading BMP from memory with LoadTexture
ERROR
LoadTexture is thinking that I'm loading the same bitmap and results identical textureID. What can I do, to oblige TV3D to load this texture without caching (or something like that).