I have now transferred the same file between the W7 machine and a Vista machine, speed averaged around the 45MBps mark, which is definitely into the realms of gigabit, but not the 1000Mbps everyone raves about. If anyone knows why, feel free to tell me but I appreciate its a different ball game.
Therefore, I think the speed issue is coming from the Terastation end. Feel free to correct me.
The display on the front of the unit is confirming a 1000Mbps connection, as is the gigabit switch with the port lit in green rather than the standard orange. The same goes for the W7 machine and its respective port. All drivers are up to date, and a look at the Lan card's device settings returns nothing unusual, its a Realtek PCIe GBE Family Controller built into an Asus motherboard.
I'm starting to feel I arrived at square one again, ah well.
Thanks for all your help so far
[Edit for spelling]