I have an update on this problem and just thought i would share it. I emailed a "Technical Expert" who works at the Renault Sport division about the 1st gear clunk problem and he has come back with something else that could be the cause. My car is now booked into the dealers for the 8th November to have this looked at and will keep you posted. Below is his reply. Please let me know what you guys think ?
"Hi there, I have referred your case to Renault Customer Services. So they should be in contact with you. Also since you have mentioned about your gearbox being replaced, this action would have replaced the first gear syncro hub. But one area that might have been overlooked was the crankshaft spigot bearing, which supports the input shaft and if it is tight it will transmit a small amount of drive / drag to the gearbox input shaft giving similar symptoms. Regards,"