I am troubleshooting for a friend and have very little Wordpress experience so apologies in advance.

I am wondering where to look to track down an issue that has cropped up with post teasers. Basically when looking at a category listing page or even a search results page the teasers are output normally except for the link that is added to the post title. Normally the link would be built from the category plus the post title, however something has caused the links to output stopping at the category level and omitting the post title, thus breaking the links for all post teasers.

Should be:

/[category]/[post-title]

Output currently:

/[category]

Any help or pointers about where to look to try to track down the source of the problem would be greatly appreciated.