I do not believe in block withholding attacks and I think that people are focusing on the WRONG issue. The problem that was discovered was the miner did not work correctly (please see below). Whether it was software (that was easily fixed or hardware which could never be fixed is not known but the owner of the miners said it was a simple software fix).
Also, it should be noted that the most recent example of this attack was apparently not an attack, rather it was probably a software problem - although this should have already been detected during testing on the testnet, so I'm not sure how "unknown" it could have been.
The problem was their software discarding shares that matched 2^32-1 difficulty or better. Anything UNDER that, they worked fine. So testnet would not have detected anything wrong.
So, I put it to you all:
1. We have someone that has bad luck (lots of people have bad luck runs and there is a 1 in 11 chance of this happening by chance so far).
2. The person is mining using tons of different hardware (so unless all his clients use the same miner brand and that brand is bad it is not likely the miners)
3. The person has software that jumps between pools to mine other coins when prices dictate. Please read the above quote. SOFTWARE problem. Their custom software did not work. But, why would they have been able to even solve one block then?
So the question is: could it be a software problem?
Still waiting to hear what Entropy's username on Bitminter is so I can take a look at his mining stats.
KOI. Work away and let us all know (my guess is you are too lazy to do it).
Information is all visible and available (if you looked instead of shooting your mouth off).
Do KOI's miners work? yes. All of them? Yes. How do they know? Because they have solo mined with them all. And then, they separated them into accounts by type of miner at pools (to make sure different miners all work). Why do you think he was so vocal at BTCGuild insisting that someone's miners DID NOT WORK?