I had problems printing the manual http://geany.uvena.de/0.14/index.html with firefox in "letter" size. It was dropping the last 5 to 12 characters on long lines. I finally printed a copy with all of the text by changing the "width" in the index.html file text:
body { background-color: #f2f2f2; color: #404040; margin-left: 0.4em; width: 60em; font-size: 90%; }
to:
body { background-color: #f2f2f2; color: #404040; margin-left: 0.4em; width: 50em; font-size: 90%; }