I've just been on the phone to my secondary bank again and spoke to Gary.
Apparently there's nothing wrong with my PIN number so he thinks something has gone screwy with the card reader but he doesn't want to send out another one in case it's something else, so I've got to call back and talk to a telephone banking bod about it after 5pm today.
I was on the phone for 20 minutes but I was actually talking to Gary for 15 of those minutes instead of being on hold!
They could do with turning the volume of their "on hold" music down a bit though... Steve could hear it from across the room! lol