Well... I had "scaled-down" the printthread.php a few days ago so it become a printpost.php and it was working for me.
I attached the file if you wanna try it out, but may be bugs that I didn't noticed.
(It was made and tested in less than half an hour.)
Put the file in your forum home folder and add this in postbit:
HTML Code:
(<a href="printpost.php?$session[sessionurl]t=$post[threadid]&p=$post[postid]" target="_blank">Print</a>)
(Of course, you don't have to use the modifications that I mentioned in my previous posts if you use this file.)
If there are any bugs let me know... I'll try to fix them, but no guaranty.