hi everybody.
i have a kindle dxg (3g versiyon)
i recently had update my kindle to 3.2.1 (on yifan.lu firmware)
but now i'm not satisfied this versiyon because it has many problems on my kindle.
how can i return back to kindle 2.5.8 versiyon for kindle dxg?
i was download update_dxg-update-os.bin (2.5.8 version 279,4 mb)
and i copied this file on kindle, but the update menu is not aviable, enable.
how can i do this

can someone do help me, please?
thank you.
(sorry my bad english)