404 error with nested category permalinks

Hey all,

My site (stereokill.net) is running WP 2.9 on LAMP, and I recently attempted to update my permalinks from /%year%/%monthnum%/%day%/%postname%/ to /%year%/%categoryname%/%postname%/.

However, when I apply the new settings, all of my links break. The permalinks seem to update properly, but when I click the post link on the frontpage it leads to a 404.

I suspect that this has something to do with nested categories, which I use widely. With the new permalink structure, it organises the posts as (for example):

http://stereokill.net/2009/reviews/album-reviews/postname

However, it doesn’t seem to work as http://stereokill.net/2009/reviews/postname either, so I’m unsure.

Any advice would be much appreciated!

Cheers,

M