I've got some highly customised permalinks on a site I'm working on for a client. The short story is that the permalinks are working incorrectly for category links. Post and page links work fine. Just the category links remain broken.
Article permalinks are set at: /articles/%post_id%.htm
Currently category permalinks spit out: /topics/%category slug%
The issue is that I've used the category slug for the full description of the category as it's been a major migration project just to get it this far.
Is there any way to rewrite the permalinks as: /topics/%category id% ?