Yes your RAM chips are bad.So there is no point to run any tests anymore...
Just replace those RAM chips with the new ones and that's it.They are really cheap lol.
And they probably have a lifetime warranty, as nearly all memory modules do, which claiming on is cheaper than buying a full new set
I would still not rule out other things. I had the exact same issue as you did, which was solved with a new motherboard.
Memtest flagged nothing, Samsung HDD utility came up clean, after numerous fomats and reinstalls the problem kept coming back, swapping of video cards, removal of all but the essential peripherals (mouse + keyboard), you name it, I did it, everything was fine. I put my PSU in another system to make sure that wasn't defective, and it ran without a single problem. Went and claimed on my mobo warranty, got a new board, all of the problems went away.
You can RMA the memory, however chances are the manufacturer will say, as Corsair did to me when I contacted them asking for their opinion (which confirmed what I thought):
If Memtest showed no errors but you were still recieveing problems, it probably isn't an issue with your memory, but send it in anyway if you want and we will have a look for you