There is a bug (or I don't understand what their words mean) in the report printer. If you have multiple reports selected and you click the print button "Print Selected Reports" they will not print.

You have to do one of the following actions:

1. Print a single checked report (Do not Check multiple reports to print)

or

2. Check multiple reports and the click and hold on the print button and select "Current Report".

"Current page" while multiple reports are checked appears to print the first page of each report.  Weird.

"All Reports" does not work when multiple reports are checked.  

If the above doesn't fix your issue then you must check your printer settings like others have suggested or

look for hidden dialogs behind Autocad.

Try setting your printer settings to something you don't want and then re-setting back to pdf.