I could not get my iBook to print to the shared HP Deskjet 6540 on our iMac. In a print dialog, the Print button would do nothing. I could only Cancel to get out of the dialog.
This posting solved my problem. It basically involved resetting everything print related.
http://discussions.apple.com/thread.jspa?messageID=727249&#727249
1. Delete the Print Preferences. Do a search (File menu/Find command) for files that start with com.apple.print and delete them. Then restart.
2. Launch Printer Setup Utility. Choose “Reset Printing System” from main menu.
3. Select (in this case shared) printer and add.
I was able to create a PDF immediately and then Print right after that.