Def check your tyre pressure. The other thing I forgot to mention is that new tyres have a wax like coating on them and it takes a about 160 - 200 Kilometres for it to wear off. You should have worn it off well and truly by now after 600 Miles (1000 KLM) but it's worth mentioning just in case it helps some one else out.
Mods, LOL you'll always find something that needs to be done