Tried a total reset ?
if you want check if problems are hard or soft ware, or want to check network locks or firmware go into the service menu, bu pressing the following form the standby screen.
*( i always put a start infromt stops me going int o shortcuts)
<
*
>
*
<
<
*
<
*
that works on any SE and is quite uses full.
SE are complete gash.
the k850 takes a few days to get used to ive found, i HATED mine when i first got it but now i love it
I was gonna get a SE K850i but when i tried one in the top, I thought it was s**te.
So went for the N95.