Lancito, are you able to connect the HDX to a PC. I found that when I browsed the drive using Ubuntu Linux, some files did have different permissions as Hi-Jack states. I was easily able to change these permissions, or delete files diectly from within Linux.
Since I use Ubuntu and a USB connection to copy files to the HDD, this is not a problem for me, and the transfer rate is quite good (around 30MB/sec). How do you copy files?