I presume as you mention adverts this is not on the BBC so presumably you are watching the reruns on Now U & Gold during the day or early evening. So you are probably experiencing the broadcaster using mandatory daytime PINs to adhere to Ofcom guidelines .. Some of the GAVIN & Stacey episodes have a 15 rating so broadcaster is using the mandatory PI N to allow the programme to be broadcast unedited pre watershed. Not sure why they would apply it after each advert break if the same episode (programme) continues.
