I actually only have 6 total units running so far, 12 individual boards. It seems to be behaving ok so far, just the missing stats. I haven't tried to figure out a manual API call yet to see if it's minera or cpuminer that's at fault.
Did you use the latest image SD flash method or manual install? thing is, while this problem happened with fresh -latest flash (which turned out to be version 0.1.8 ), the problem persisted even after I updated to 0.1.9. But hey it could still be an image flash specific issue. Especially if minera update doesn't update sandor's cpuminer. So let me know how you got your minera up and running to see if there's a correlation there. Otherwise it is a core minera and/or cpuminer issue.
I used the latest image from Mega as of about 8 hours ago. I'm up to 20 individual blades(10 units) now and it's mining fine, seeing 53MH at 825mhz. Will keep an eye on it, I've heard of blades slowing down over time on cpuminer...