Yes it can and as far as i know its easy to do, have a look in the TT community forum as plenty have done it.
I recently exchanged a faulty HG633 for the D-Link 3782 and my speeds etc are much better it may be worth telling them you are having problems and ask for one so you can test it - https://community.talktalk.co.uk/t5/Fibre-Broadband/...