CM10.1.3 RC1 is Android 4.2.2.
Right, but it was an update from 10.1.3 to 10.2 which is Android 4.3.
It's a known bug with 64 GB FAT32 formatted card, which I have no idea why it happens (and I don't have access to a 64 GB card). If you format it as exFAT, it will work.
Will do that, thanks. (Edit: Just wanted to add, it works with exFAT)
Could you please generate a few FCs more, so I can easily spot them?