Delkin SD card problem

Hope someone can shead some light on this. While the 'Delkin Devices 32GB Elite SDHC UHS-I' is on the official approved list for the Black Magic Pocket Cinema Camera, the Delkin 64GB Elite drops frames like crazy in ProRes or Raw on playback. I now notice that the approved Delkin 32GB Elite SD has 95mb/s read and 80mb/s write speeds, while the Delkin 64GB Elite SD has a 95mb/s read but only a 45mb/s write speed - I didn't expect the increased capacity to have a slower write speed. I'm assuming, of course, that that the write speed is the problem but being a newbie to this I'm not sure. Has anyone tried the Delkin 64GB SD?
Thanks!

Thanks for the reply. So, it looks like if you want reliable use of the camera in ProRes and RAW, SanDisk Extreme Pro 64GB it is.