Thanks for the replies everyone.
Can't see it as a result of thermal changes in the general fabric of the cooker as it seems to happen within the same timespan regardless of whatever unit is energised.
No regs require an RCD, just seems prudent - and no, I'm not a professional electrician and I won't risk aq dodgy cooker if the RCD says it doesn't like it. Sad thing is my gut feeling is there's nothing wrong with the cooker and the RCD is being overly sensitive. Don't want to trash a good cooker for that reason.
Additionally I now use on the same circuit, a Baby Belling that used to fire the RCD in my parent's house but works as good as gold next to this damn AEG cooker...
Ain't no continuity here..!
