Beware, ageing rock stars and dodgy TV presenters. Watch out, teenagers and others with a taste for exotic digital media. The new Windows Media Player 9 may not be your friend. A pal of the Diary -- don't worry, Adrian Mars of Hampstead, your secret is safe with us -- reports that WMP 9 is unusually anal about its media files. He downloaded the software and asked it to find his media files and add it to its library. Which it did -- but it also found files that he'd long since deleted. We're still not quite sure how it does it, but it seems to pull information from cached lists of names created by earlier copies of the player. The result of this industrious behaviour is that all those late-night downloads one pulls off the Internet for a few minutes' viewings will apparently be in one's library. Oh no, you might think as you hear your mother bringing a nice cup of tea into the study, she's not ready for my fondness of Tom of Finland - The Animated Series (*), so you highlight the offending files and hit delete. Phew! They've gone! As if. No, WMP 9 doesn't give up its prey that easily. Next time you visit the library list, the items are back. You have to right click and choose 'delete from library'. Be careful out there. (*) Example chosen for illustrative purposes only. On no account go looking. Tom of Finland is very rude. Adrian Mars of Hampstead most certainly would never think of such a thing, and we regret any apparent connection that may be implied.