Sometimes when I am posting an article to a new category with WordPress I will notice the category permalink does not look as I expected. For example instead of "wordpress" it may say "wordpress-2".
Why does it not just tell you where the slug is and ask if you would like to either change it to something else or delete it. Well after some soul searching I found it. I posted this becuase this is the second time this happend to me while using WordPress and it took me longer to find it the last time.
Posts -> Post Tags – and find the duplicate and either rename it or delete it.

You have just helped me solve my little dilema. When I created my blog I added the categories first. Since then I have added a load of tags. I then went to add some more categories and found that it added “-2″ on the end. Infuriating. However read your post, deleted the tags and Bobs your uncle.
Many thanks
David
Never commented on a blog before. But had to this time. A simple solution to an annoying problem. Thanks man!
Thanks for the heads up. Simple solution to something that was bothering me.
Ha! Finally..
Thanks, mate. Sad that I couldn’t find the solution before.
perfect! thanks so much.
Glad to assist, I decided to change the way I was using categories and just stick to using tags for grouping related post a few weeks ago. I understand this is not your solution but for those just building a new site it could be helpful.
For those interested in reading more about WordPress tags and Categories check out this article:
http://en.support.wordpress.com/posts/categories-vs-tags/
Thanks. I have upgraded my blog from 2.x to 3.x and I haven’t tried fresh install.
I’m having this same issue with my blog:
http://blog.petrilopia.net/
But my problem is bit more complicated… I can’t remove that tag cos I really need it to be one of my tags… Or at least I think so… Is there any ways to use same slugs for Categories and on Tags?
Hi Petri, This is a very interesting problem. This is also happening on iLERTECH and my dev server.
I just tested this on a new WordPress 3.0.1 install and all was working as we would expect “wordpress” slug for both tags and categories. I thought it odd since they are different urls “category/wordpress” vs “tag/wordpress”.
I wonder if this is a problem for those who upgraded from v2. I tried to import my current site into my dev site but was unsuccessful and had an error with my tags ever since.
Did you try a recent failed import using the WordPress admin tools?
Did you upgrade or is this a fresh install of 3.0.1?
Nick
Hey Henk, Glad this was helpful.
Thanks, was looking for this, couldn’t get rid of the ‘-2′