The mid code on those DL disks is CMC MAG D03. We recommend using Verbatim brand double layer dvds, which come in two varieties, the 2.4-6x MKM 001 disks, or the 8x MKM 003 mid code.
Other types of double layer disks are hit or miss, mostly miss.
The only other DL media that have found favor on these forums are the double layer disks made by FTI and sold under the Falcon brand. They are available online in the US, but not in local stores.