Hmm, that's odd because I also recently purchased a Flexnet 1TB and have had no problems transferring files up to 3.9Gb per file (due to FAT 32 limitation) of movies, music and backup. Like Davo, I thought the limitation for FAT 32 is 4Gb per file size or is it not for this Flexnet?!? The transfer is slow though even on a 100mbit LAN. This is not Gigabit like the Livestation models. Perhaps you had the sleep function set too low?!? 750Mb over what LAN can take more than a few minutes, sometimes an hour. The sleep timeout function works up to 60 mins. Disable sleep (under eco management) and try again
Upgrade your firmware also to 1.4.7. I had found with my older 1.4 firmware that occasionally during file transfer, the drive itself will go crazy into a continuous loop and the blue drive light flickers like crazy. I thought at first someone broke into our firewall and is accessing the drive. When the blue drive light is flickering like crazy, the transfer will stop, but accessing the web service is fine. Since upgrading to 1.4.7, it hasn't done this.