My initial thought / question is whether this happens with ONLY Acrobat, or do other applications show this way as well? Also, does perhaps maximize and restoring the Acrobat window change this? If that window is dragged from monitor #2 to monitor #1, does it display properly? Any further information or descriptions might be helpful in troubleshooting.
This behavior only occurs with Acrobat. This issue occurs consistently on the one monitor, when you drag the window over as well as when you minimize/maximize. The issue will generally go away with a reboot but will eventually return.