Moving this discussion to the Printing & Prepress sub-forum of the Acrobat forums.
It sounds like a double-sided printing problem with the printer. I am assuming that AA9 is not set to print double sided and that you have run into a default that seems to be the case for AA X of double-sided printing. If the latter, try to turn of double-sided printing. If that is indeed the case, you might check the paper loading. Some paper has to be loaded with a specific side up for double-sided printing or the paper tends to jam.
I don't think this printer does double sided -- so I am surprised about this. When and if I load Adobe X, I'll keep this in mind!
Thank you --