I found this a bit annoying, but the conventional method of converting .lit files to PDFs is to use open office or abiword and copy and paste the contents from firefox, then choose save as PDF or export to PDF. As a result I wrote this shell script, it has two dependencies, convlit and htmldoc
sudo apt-get install convlit htmldoc
Then you want to download the attachment(to your home folders a good idea), drop into a terminal and run:
chmod +x lit2pdf.txt
sudo mv lit2pdf.txt /usr/bin/lit2pdf
Then find any .lit file you want, right click it, and open it with "lit2pdf", using the custom command box. When it is done you will be told how many files were extracted and asked if you wish to delete the .lit file now.
Let me know if you get any errors etc.