Fixed width last post table cell

[squishi]

I am unable to assign a fixed width to the table cells that contain the last post info.

I've already tried to give both the table cell (td) in the first row and all other rows a certain css attribute ("style='width:200px'").
When the page is loaded, those cells collapse to the width that is determined by their text content.
How do I expand those cells so that they all have the same width?