Thank you for the responses.
Maybe I should clarify, I had no problem with the hotel pre-authorising the mastercard on my PC account - but they wouldn't because I did not have it with me and they insisted on swiping it (wife was shopping with it). Usually this does not cause a problem.
This was the first time an agent has gone up to my room before allowing me to check out.
It would be easier to understand if this was my first IHG stay, but I've been a loyal member for 12 years and have a thinning hair line to prove it.
I think the hotel genuinely had a problem with a previous guest who paid a cash deposit so I fell into the same high risk category, regardless of the 700+ previous nights on my PC account.
pauleeepaul asks what is a RA doing in a HI Express

?
Trying to save a few pounds by redeeming 5000 points

My old Ford was sandwiched between a new Jaguar and Aston Martin, I must be in the wrong business.