I used both Mac and Windows on my MacBook Pro; on the Mac system when I used Adrobat to print directly from a PDF (I have visited several websites -- all the same result) the default that comes up is 4 x 6 which means that a letter sized document is tiny, tiny, tiny. However, if I go and copy this PDF to, let's say my desktop and open with Reader, it will open properly -- letter sized -- and I can then print properly. This is only with the Mac. With the Windows side, I have no problem. Can any one tell me what is going on? I have HP printer, Office Jet 6400 series. Mac OS X 10.5.8 and Windows XP. I always update any time I get an alert from Adobe. I believe I have version 10.1 Hope this helps.
It also wouldn't hurt to check the Page Scaling in the print dialog, to see if it is on None, Fit to Printable Area, Shrink to Printable Area, etc.
Also, out of curiosity, what page size is the PDF reporting under File > Properties (in Description)?
Kelly McCathran
Adobe Community Expert
Certified Technical Trainer+