Can someone clear up this issue please?. I have bought a new Zanussi electric cooker with a glass ceramic hob. In the user manual it says "do not use copper bottomed pots or pans as these can mark the ceramic hob surface". BUT on many cookware websites including LAKELAND (uk) it says in the description of their copper pots "for use on ALL hobs (except induction)!. I am really confused and I only own copper bottomed pots and didn`t want to go to the expense of buying new pots...thanks!