xperia overlay ray problem sd card

I have a problem with the new rom overlay kitkat 4.4 on ST18i Xperia ray, I explain: when I move an app from internal memory to SD card (using the same option ROM) to restart the android app icon disappears. I tried to put the write permissions on sd card by editing "platform.xml" but nothing, nothing changes. The app continue to operate in the same way the sd card. For example if I try to download something with the browser in the "download" folder existing on sd, the browser tells me: not enough space, and not download. If, however, exhaust the files in a folder created by the browser in the sd then it does.
I am grateful for any help.