Permalinks repeating parent category in URL

Hi all,

I have just set up Permalinks and they are working as I had hoped when browsing individual posts. Here is my custom setup:
/%year%/%monthnum%/%postname%/

The problem is when I click to view all posts in a Sub Category, it repeats the parent category in the sub category of the URL. For example:

I have a parent category called “links” and a sub-category called “browsers”. Here is how the permalink URL displays:

/category/links/browsers-links/

However, it should be:
/category/links/browsers/

without the hyphen and links bit. Does anyone know a way around this?

I’ve done a few searches on this and come up with nothing, so would appreciate even a link to another post that will solve it.

Thanks