I get this error when downloading HD files from the itunes store. When first trying to download them I get error code 1309. I do only get this code when 4 GB of the file is downloaded and wont download the rest.
I use mac mini with 2.3 GHz intel Core i5 with memory of 2GB.
There is 400gb free on the hard drive of my mac mini and i use a samsung 1TB extrenal harddirve connected via USB that stores all my itunes libary.