[MT-AU Public] Windows7 crazyness

Hi All. I have a RB2011 running an ADSL link via PPPOE and the modem in bridge mode. I have 4 macs, handful of Linux machines and androids all on the network. All working fine. I have one windows machine that has full speed local LAN but almost no internet less than 1k. I put this down to MTU but my mss adjust is in and working. I am able to browse fine if I use the web proxy in the RB but that's not a solution. All other machine/devices just work. I've tried lowering the mtu on windows, adjusting and tweaking the mss mangle rule but nothing has worked. Anyone have any suggestions or thoughts? Sent from my iPhone