Sorted !!!
After ripping my hair out all day - i managed to get it up and running
The Netgear WG602 Wireless AP COULD NOT work in the required "bridging client" mode with the stock firmware.
I reflashed using an open source firmware, that provides a solid "bridging client".. now i simply connect the Netgear in the tm600's ethernet port and away we go!!!
A long technical way round but saved me £'s...
Thanks again Silverfox