It's harder to get on del.icio.us/popular these days

The folks at del.icio.us must have made it harder to get on to the del.icio.us/popular page over the past few months.

When I first was listed on there you simply needed 10 bookmarks within the past 24 hours. I was looking at the article I published yesterday MySQL Optimization Hints and noticed that it has 28 bookmarks over the past 24 hours, and has not yet been listed on the popular page.

It appears that they still require only 10 recent bookmarks, but they have shrunk the window for what they call recent. It must be down to 10 bookmarks within 12 or 6 hours. Does anyone know the specifics?