This is what happens when you move the focus to your tumblelog for too long, your main site gets neglected and then when you next look at it is all screwed up. It seems like I’ve lost my carefully structured categories somewhere along the way (and this site has been upgraded gradually) — and I am not alone. As I haven’t imported all the old Blosxom posts (yet) I am not sure what do — start from scratch or try and import the old Blosxom posts again to regenerate the categories. We will see; for now I have just given the categories generic names so at least I can get some idea of what they are (ie arts/music should probably be the largest one). As for tags, they are a waste time of anyways, so no chance of wasting even more time on trying to get them back.
Note to self, back up and sanity your sites once a month.