First to answer: no i dont see a difference in the Receiver
i did 2 things today, i installed the wifi Adapter and during this i updated to the latest Firmware. After finishing wlan testing i tried the remote and what should i say, problem solved. . The first Frame i bought, the troublemaker, the Frame works now as good as the second one. I am sorry i cant tell if it was the Firmware or the new chip, but now, for the first time, the unresponsive one behaves as good as the second one. I am puzzeld.