After noticing that the likes of AppMonster, ES File Explorer and Ttorrent were not writing/deleting to n from the external SD card.. Did a little digging around to see how permission are set.
Here's how to the fix external sd card write permission for all apps ::
Using Root Explorer navigate to /system/etc/permissions/
make sure filesystem is set to rw
Open up platform.xml in the text editor
look for the permission 'WRITE_EXTERNAL_STORAGE'
there will already be a permission group "sdcard_rw" but we'll create a new group under that one.. so add
<group gid="media_rw" />
save the file
reboot MK802
all should be fixed and apps like Ttorrent will be able to write to the extsd
if you're using something other than root explorer, make sure the 'platform.xml' permissions are set to the way they were before editing... don't want anyone getting locked in a loop.