Have you tried changing wireless channels? "smart wireless" puts me onto channel 1 , using inssider i can see that there are two other routers near me on the same channel (so its not that smart).
After testing all the channels ,getting an actual data transfer speed of 65mb/s , i found that on channel ten it leapt up to 135mb/s . Which is much closer to my adapters potentiol of 150. On this channel my speedtestd shot up from 42 down to 58 , giving almost as much as my 62 hard wired maximum.
You can see your data transfer speed on the wireless channel page so you can see if it has any affect after each setting has been applied
Just something to consider looking into , dunno if it'll help in your case , also it might be an idea to change to 40mhz although i read this can affect wireless range.
Cheers for all your input.
Having tested the wired connection again, this reaches 72Mbit/s out of the 77Mbit/s, which is terrific, so I now know that it is a wireless issue. I will play about with the inSIDDer program and change wireless channels in HH Manager to see if this improves things.
A further update: I am now achieving 60Mbit/s on wireless, so I am very satisfied with this. I might decide to connect via ethernet cable in the future as the extra 12Mbit/s might come in handy.