Cell padding disappears on Firefox after scrolling past element

I have a Special Heading and Code elements within a column element. The padding for the column is set to 5% (top, bottom, right, left). In the firefox browser, when the page first loads, the special heading and the rendered elements from the code block are formatting properly. However, if I scroll down the page and move back up the page, the top padding seems to have disappeared and the special heading is now almost at the top of the cell. How can I fix this?

Proper Alignment of text: http://snag.gy/rWzKy.jpg
Improper Alignment of text: http://snag.gy/DHonu.jpg