Hi Brian,
Unganged is the better way to run your RAM so that shouldn't be the problem.
As I have mentioned before though, the problem could be due to the RAM or the Memory Controller on the CPU did you try running the RAM as I suggested, with the sticks in slots 1 & 3 or 2 & 4 to see if they then worked?
OK, I had overlooked your suggestion, which I have now carried out with the following results.
RAM in sockets 1 & 3, Four passes of MemTest - No Errors.
RAM in Sockets 2 & 4, Pass 1 produced an error report at 001a556f34 - 4517.3MB Error bits 00040000
Pass 6 produced an error report at 001e556f34 - 4581.3MB Error bits 00040000 (Not quite the same location).
So finally I see an error, but would I have seen an error in sockets 1 & 3 if I'd run more than Four passes of MemTest?
Next question, What level of errors is acceptable, if any?
Besides which, None of this really resolves the situation that the system will only boot first time with one specific stick of memory installed (in any socket), and all other combinations of memory mean I have to go through the power on/off/on booting method.
Each pass of Memtest takes over an hour to run and I'm getting pretty frustrated with not being able to use the system, since I have work that I need to do.
I'm sure I have enough grounds to request the memory is replaced by the supplier, so I'm going to contact them regarding an exchange. At least that should absolve the RAM from being responsible.
Regards,
Brian.