The USB stick may be FAT32. FAT32 drives cannot hold >4GB files irregardless of free space.
If both are true, then your USB stick cannot hold the AVCHD ISO. Try Extract the AVCHD ISO to your PC HD, which should be NTFS (which CAN hold >4GB files).
The USB stick may be FAT32. FAT32 drives cannot hold >4GB files irregardless of free space.
If both are true, then your USB stick cannot hold the AVCHD ISO. Try Extract the AVCHD ISO to your PC HD, which should be NTFS (which CAN hold >4GB files).