Thank you for the post janner43. I followed it earlier without a hitch. Despite knowing how to do the reset already, I wanted to do this in the optimum way possible as per all you guys running ICS without any major problems to speak of.
Another question that I should have considered before the factory reset, doh!...I used Titanium to back up apps and data. Obviously, as it needs it to run, I will have to root again in order to restore anything. Is rooting likely to cause any problems? Have any been reported that you're aware of? It's no biggy as I can factory reset again if needs be, but wondered.