OK.... a lot to take in here so sorry if I missed out anything from anyone's posts!
This is my graphs at the minute (ignore the packetloss, something tripped the electric!):
Test Hub
Own Hub
There doesn't appear to be any craziness on the test hub at the minute, but it would always take a while to build up anyway, it would never just start going crazy after it's been plugged in.
At the moment, bar my less than perfect graph, everything seems OK. So I'll leave it until it goes crazy again.
We only have 3 things connected to our hub at the minute, boyfriends laptop (wired), my laptop (wireless) and boyfriends ipad (wireless)
The test hub only had the NAS drive connected (wired).
The thought of someone trying to or having access to the NAS drive scares me... :-/