API end device hanging during writing

I have problems with XBEE series 2 writing the parameters in
API mode. It hangs when it"" Setting AT parameters"" show on the X-CTU window.
All other works normal.
I ticked the API box and the always update firmware box.
This problem both for the coordinater 1147 and the end device 1347.
Has some one any clou?

ps. When I use AT no problem.
XBEE 2.5 Znet OEM RF modules HV 1944

To whome it is of interest.
Trying even harder to solve my problem the following.
The problem i had occured during my search to have
my end device battery operated in sleep mode and must awake on input change. This all at minimum battery load.
I ended up in the problem hanging during saving to nin volatile memory.
So, now I have solved the problem i think.
The coordinater is in API mode end the end device in AT mode.
Both now possible to save to non volatile memory.

But another problem occured.
The minimum load on my XBEE is 17 mico amps. which is far from the 1 microamp.
In the parameter list all parameters which are possible to disable are disabled. Still 70 micro amps. Has any one any ideer what can couse this ???
Any help is welcome.
All this to have my XBEE running al long as posible on batteries.
Thanks in advance,