I recently came across an unusual problem when using internal links on a WordPress site. The link in question linked from one page on the site to a specific section on another page of the same site. When this link was followed there was an error with the page layout. More accurately, the new page layout was technically correct and the rest of the site was wrong.

I struggled for a while trying to find the source of this problem. I looked at the ‘error’ page in firebug and compared it to a normal page on the site. On all other pages there was a mysterious magin (or padding) created at the top of a div but when this page was visited from the link the margin/padding disappeared.

Long story short, the div in question was set to overflow:hidden. When I commented out that line, the problem resolved itself. Why? I don’t know. Can anyone shed any light on this?