Firstly, I'm amazed that anyone actually reads the CC Magazine. Mine is skimmed and then immediately put in the recycling.
Here's a comment I put in a thread a few days ago:
"Just to echo what Derek, said, I think it's good policy not to park the caravan (or car for that matter) for any long period of inactivity with the handbrake engaged as brake shoes and pads can stick to the drums/discs and be a pig to release. Clutch plates are also prone to this."
Last year you were lucky as if the brake shoes had seized to the drums, you would certainly have known about it when you tried to move the van.