I'm not to sure about the 800AP+ firmware. All I can recommend is that you use the first version of the 800AP+ firmware that was released with the repeating function. For me that was v2.50 on the 900AP+ - I don't know if firmware v2.18 on the 614+ is an issue or not but I use v2.10 and it all works. So I'm reluctant to change anything. Hay try it you never know!
Since I posted my changes it has been running perfectly.
I certainly understand you putting the repeater back in the box mine was very close to heading there too. You could always exchange it for a 900AP+
