Acrobat X deskew not functioning

My library recently updated from Acrobat 9 to Acrobat x on some of our scanners. When I tried out the new version, I have found the deskew on Acrobat X does not seem to function even when it is turned "on" in the optimization window, when I make scans to PDF from paper documents. I had our IT person "downgrade" one of the scanner setups back to Acrobat 9, and the deskew problem disappeared. I have tried several scanning stations, and the deskew on Acrobat X simply doesn't seem to work. Has anyone else had this experience? I have asked our IT to downgrade all of our production scanners back to Acrobat 9 until the problem is resolved, since deskew is crucial to our digitization projects. I have listed our version as 10.0 in the dropdown below; actually I can't tell if it is that or one of the updates, since it just shows as "Acrobat X Pro" in what I can find in the Properties window.