Thanks Fred,
Didn't realise there was anything dodgy about them. The first time it happened I didn't even realise until I checked my passport a week or two into the holiday as I remembered the standard visa was only valid for 30 days and we were there for 5 weeks. It's not as if I've ever asked for it, in fact when I was offered it in September last year I declined it as I was only staying for 2 weeks.
Maybe the reason I've never been questioned is that we've always left as a family and approached immigration together
