A note that might be of interest:
I've been warned that there is a big worldwide piracy on the scan disk extreme. Make sure you got a legal product, specially if you buy over internet.
Then, they might be issues with the Sandisk SDHC Extreme PRO UHS-I, in fact the only camera to date that can take full advantage of this new "standard" is the Nikon D7000.
But things are not as simple because a quick search in internet showed that users have different experiences with the hacked GH2,
for some this card works well, for others it does not and they recommend to stick with the 30MB version.
(I suspect that a sound bit-rate setting might cause a prob or it simply could be that their cards aren't legal)