Cannot Print Double Sided Adobe 7

Starting about two weeks ago everything I sent to the printer started coming out single sided. I tried another printer: same thing. I tried Word. It still prints double sided fine. I asked others in my office who use Adobe Acrobat Pro if they were also having problems (our network can change overnight and sometimes goobers just show up). They can still print double sided from Adobe, but I cannot. Therefore it seems to be something with my machine.

All of my printers are set to double sided being the default. Even if I go in and double check properties before I print a pdf, I still get single sided. Also it does not seem to matter how the pdfs were created. If I download it, single sided. If I print/convert to Adobe, single sided. If I use the Forest Service Pdf Creator, single sided.

So I need to do some trouble shooting and really do not know where to start. Somewhere, something got changed. I need to figure out what that is.

I have run the Adobe "detect and repair." I have downloaded the most recent upgrades (it did this both with 7.0.9 and now with 7.1.0). I am on Windows XP with an IBM laptop.

Thanks.