Are you pencil modded? if yes, seems like the power bucks dont like it very much.

Try removing one from each lane(you should have 4 lanes), leave only 3card/lane and add them one by one testing stability, see how it does, also cleaning the oxidation from tha card pads helps.
If it works with 3 cards/lane you should consider another m-board.

Check above posts, i can make you one of those, they are not pretty but they work, also youll need another Rpi.
Pm if interested.

Well you are not going to like pricing ) ... one asked through pm and i said the following:
- As it is 1/4th of a full m-board it should be 1/4th of the price meaning 50 euros(as a full v2.3 m-board is 200 euros)
- and i could to a full one for 150 euros

... before judging the price please consider that i built them in my spare time and i have a job, the manual labor on these is not easy,
they are not massed produced even if the BOM on this is about half of the total cost.(takes 2 days to make one from 0, if the only thing youll be working on is the m-board)

also consider that they are not in stock, look what happened to DDR Ram pricing, as ddr3 came out, ddr2 became more expensive because it became more rare.
i am not trying to explain myself, i just want people to take in consideration some facts before saying ... ohh it too expensive... or things like that

I am building a second one, but i cant seem to find how the hell are those ISA 10 contact slots are named, so i dont have to cut actual ISA slots in pieces... desoldering them from motherboards is F...ing time consuming.

If you like to try my second one(aka test it) i could send it to you, if you like, you keep it at a price, if not, you send it back.
This offer is also for tarmi as he asked for one as well through pm.

Is there already some one with ... some rev2 test boards ?

I got the 32 dev. chips today ... :-)

sent them straight to wasp ee's

I would try one h-card at a time in chainminer to see what chips are working and which are not doing so well.
Check for oxidation on the pads, clean them with sand paper or put a thin film of solder on them(not the best solution but works for a while, then you have to sandpapaer again).

I have a home made m-board and found this to be a problem, i will solder the pads with wires once the setup is complete... so no more oxidation problem.

Also i have found that lowering the iovdd to 1.6...1.5v makes the "50% drop in freqency detected, reinitialising" error in BFGminer and the miso errors in chainminer go away. I dont know why... so dont ask.
as i been told by intron, the mAmps required by each chip decreases with voltage and the lm2596(3A) or the lm317t(1A) can take it... or i have o source of noise in the iovdd line(no osciloscope to check) ...who knows... lowering it just worked for me.

I know its not an option on the retail m-board, im just sharing my findings.

I tried bfgminer as the proxy and though the shares make it to bfgminer, they're all discarded as hw errors. Not sure where the problem lies as I've encoded credentials into jobconnect. Perhaps I'll throw the question at Luke-jr at some point.

Update:
Nevermind THAT ^^^ CGMiner works a treat now on bitfury rigs. Bye Bye chainminer and the lamo proxy. Thanks ckolivas for the awesome miner! Finally got some cgremote action on bitfury rigs. Huge thanks to Kano, who apparently did the bulk of the work to the bab driver.

https://bt.irlbtc.com/view/28402.msg4726840#msg4726840

How did you get Cgminer to work with bitfury h-cards?
I only managed with bfgminer, cgminer only wants usb stuff

Yeah cgminer does work with these cards, ive been testing it now and then, but have always returned to chainminer. The reason is that even though the speed looks very good after a while it tunes itself to max speed (385GH/s vs. 420GH/s max speeds, chainminer vs cgminer), after a day or so it goes below chainminer speeds. I guess restarting cgminer daily would fix that, haven't really bothered as chainminer just rolls on on autotune. And cgminer does have some options to tune bitfury cards manually, but currently i just want my rigs to run without constant tuning .

What options are you starting cgminer with?