Bill,
I could not reproduce the bug even from my CentOS7 Docker Image. Could you check reduxd.log ? It will be at where you specified on the webserver /etc/myami/reduxd.log
Look for lines like this of what you did fft of.
REQUEST: pipeline=standard&filename=/emg/data/leginon/19sep13z/rawdata/19sep13z_vs.mrc&power=1&maskradius=5.12&shape=512x512&scaletype=stdev&scalemin=-5&scalemax=5&oformat=JPEG&overlaycolor=0.35
power=1 indicates that it is doing a power spectrum. shape should be 512x512 which matches the shape of the window it output to. Your window is shorter than I expect.
If that is correct which I think might be, then maybe there is a difference in how your browser render the frame because it seems that it truncated the overlay image but scaled the redux produced image to fit the window.
Please inspect the html element (show source) from your browser. If you find where it makes the frame, it should something like this (It contains fft=1:
<img alt="empty" name="v1img" src="http://127.0.0.1:8001/myamiweb/getimg.php?imgsc=getimg.php&preset=all&session=3&id=6&t=80&tg=1&sb=1&fft=1&xp=100&flt=default&fftbin=a&binning=auto&m=1&r=-1&g=1&opt=2&df=1&lj=0&gr=default&autoscale=s;5&conly=0&s=512" border="0" hspace="0" vspace="0" width="512">
The important part is the last one, The viewer only defines width not height so that it fits the height proportionally.
The last is to check your fftw-devel installation version I have 3.3.3