Have HMC150 - updated firmware to 1.20 and tried to format new Kingston 16gb class 10 SDHC cards (bought 2 while they were on sale). With 1.20 received message that the card could not be formatted.
Just updated firmware to 1.21 and now I get "check card".
Card status says class 10 but incompatible. I'm surprised that a card from one of the leaders in card manufacturing wouldn't be compatible. I have a Kingston 32 class 4 that has and does work fine, so I had no reason to think Kingston would be a problem.