I just got an HM 700 and the camera is awesome. Huge step up from the Sony FX1. Any who, I bought two Sandisk 32GB class 10 cards for it. Now here is where I think the problem may be. The card is actually a micro sdhc card and I have it in an sdhc adapter. But every time I record, when the card gets down to about 80 mins remaining (starts at 111 mins) I stop the camera and it says invalid media. Is this because of the micro sd? Love some feedback and thoughts.
Although I've never used one in any of our three 700 cams, I've gotten the "invalid media" message on sub-brand (inexpensive) SD cards.
JVC recommends Toshiba, Panasonic and SanDisk. I've used those as well as Transcend without problems. Cards must be formatted before they can be used. Consider a full-size card in one of those brands; prices continue to come down.