I was once again annoyed by the fact that WordPress doesn’t allow dots in post slugs. Luckily, this time I hadn’t published the post with a botched URL yet. (I don’t like changing permalinks because they’re meant to be permanent; cool URLs don’t change.) A quick googling pointed me to a post in the WordPress support forum with a reference to the Periods in Titles WordPress plugin.
The plugin works great and allowed me to post http:///2007/05/30/jeroen-dekker.com with dots and without problems.