data transmission failed after pin hibernate

In my case, I have two modules of xbee pro s2b, one the coordinator and the other the end device. Both of them work in the API mode. The parameters are:
coordinator ID–15,CH–800,BD–4,SP–AF0,SN–FFFE
end device ID–15,CH–800,BD–4,SM–1(SLEEP_RQ is connected to the ground so it is wake on power supply)
others all in default.
I use an embeded system of MSP430 to power on the end device every 10s to send an API frame then power off. The coordinator is connected to the UART port of my computer so that I can receive the message from the end device. Then strange things happen.
If the destination address is set to be 0x000000000000FFFF in the programm, I get an API frame every 10s. If it is set to be the mac address of the coordinator, the API frame is not out from the UART every 10s as predicted but sometimes. The transmission status(0x8B) tells me the end device sends the API frame successfully. It seems to me that the coordinator drops the message.
What happened? Someone could help me, thank you!

If you turn off sleep mode, does it work? That is, if you go from a Router to the Coordinator, are you able to communicate properly.

It is the same result with the router. I don’t understand why it is OK with broadcast transmissions but wrong with unicast transmissions. My coordinator is plugged into a board of XBIB-R-DEV. The RSSI PWM indicator light blinks every time the end device sends a message, but the RX indicator light doesn’t. It seems to me that the coordinator drops the message sometimes. The destination address in the API frame is right anyway.
What’s more, my programm works very well with XBee®/XBee-PRO® RF Modules. The differences between xbee and xbee-pro s2b are:

  1. xbee can work in a sleep mode of 0.
  2. The TX API frame is 0x00.
  3. The RX API frame is 0x80.
    So, is this a bug of xbee-pro s2b?

Can you provide the API frames you are sending? Can you also provide the firmware version of both modules, the AI value and the 64 bit address of both modules?