I think this will work: in the upper right hand corner of each post is a number. Click on it and it will open a new window with just that post in it. Then you can print that window.
Another idea, and this will work for any web page or file: highlight the text you want to print, then select print from the "file" menu (don't use the print button on the toolbar.) When the printer window comes up, choose "Selection" under Print range. This will print just the text you have selected.
HTH!