I also had problems with my SD. (2532 iws) 5.2.0 both with hacked firmware from china and original firmware with mtd hack.
I had bought a 64 SDXC card from AE. The card works fine when I insert it in my laptop (adapter) . Pretty good speeds actually.
However, in the cam after the format process starts, the % number moves up till 26% and stays there for a long while and grey screen. Then after reboot it shows uninitialized.
I tried with a Sandisk 16 GB and works fine. I wonder if this happens bc of the SD card or the 64 Gig size or SDXC or what?