Printing problem: tons of blank pages, etc.

I am having a strange printing problem with my Mac that just started today.

When I tried to print a 2-page document (it was an adobe pdf file), my printer printed literally about a ream of paper. Most of the pages that came out were blank, but some had 2 lines of strange print running diagonally across the page on a downward slope.

I tried to print something else (this time an internet file), and the same thing happened.

I reset my printing settings, but that did not help--I just tested printing and went through another ream. I am using a shared printer, and no one else is having problems printing. It seems to be my computer.

Does anyone have any ideas as to what is going on, or what I should do to fix it?

Thanks.