Leeneia - I wasn't going to mention the event by name, but everything does seem to be resolved now.

The event is Thundersprint 2012, an annual international motorcycle rally which takes over the centre of Northwich, Cheshire UK over an entire weekend in May. It's big.

This year the Music Stage organiser is new to the job, and only asked me to take part a few days ago (I've frequently been involved in the past). It seems that some misinformation resulted in her sending out forms to entertainers which were really intended for traders (burger vans, fairground operators and the like).

PeterC - please read my second post. A DISCLAIMER, not a risk assessment is all they require. In other words, if I injure myself doing something daft I can't sue... but if the stage collapses due to someone else's negligence, I can.