Baking with plastic wrap?

Anne just wrote a funny post about a disastrous cooking evening, which was topped off by trying the method in Nigella's new book, Feast, for lining a cake tin with plastic wrap. Her wrap melted instantly and leaked into the cake, making an awful-sounding toxic mess. The amount of comments left condeming this wacky idea has galvanised me into action....

...because, yes! This method actually *does* work! At least, it has for me.

Wtiness! I tried her method a few months back, convinced it wouldn't work. I mean, it sounds SO stupid! Lining a cake tin with thin plastic wrap you use to wrap sandwiches?? Did she use some amazing super-strength plastic wrap you can only buy in the UK?? She must have gone crazy! I decided to give it a go anyway; I didn't have much to lose if the cake failed.
The first few seconds were hairy as it seemed to curl up and looked like it was about to collapse in a melted mass, but something happened...it stopped - and just sat there happily lining my cake. In fact, after taking the cake out and cooling it, I noticed the plastic wrap had actually become harder and more solid! I've taken to using this trick a lot now, because I keep forgetting to buy more greaseproof paper when I'm at the supermarket.
So, I wonder why it worked for me (and Nigella) but failed miserably for Anne? I used a metal cake tin, but I'm sure Anne did too. Is the type of plastic wrap so different in Sweden? I just used the bog standard stuff you get in a roll and get into a furious mess with when you can't tear it off cleanly and stop itself folding over and sticking to itself...
I'm really curious....why this dramatic difference in results??

In other news - I receive a late birthday present from friends of a $50 voucher to use at Books For Cooks! Yay! I have a few ideas, but does anyone have any must-have recommendations?