Most of the time, I have seen this with HP All-In-One printers and usually one of the above options seems to correct the problem. Short of buying a new printer and crossing our fingers, I am not sure what else to try. We have updated drivers, reinstalled Reader (yes the user is using the freebie), tried adjusting the limited settings available on Reader. to nail down the thing that causes it to go haywire.
And it only happens occasionally and seems to be no consistency between the various documents in terms of format, fonts, content, etc. I support many locations and the conditions seem to vary slightly, but this latest one involves multiple page documents where the last page or two is filled with garbage but the pages before are fine. The display looks fine on screen, but when printing something is going awry.
When printing PDF documents, occasionally the printout will show garbage characters (like random letters, number and special characters) in place of the original text on the PDF. I looked in the forum but could not find any reference to this specific issue. I apologize if this issue has been addressed.