One of my users is running into an issue where attempting to edit PDFs results in the program freezing and forcing him to reboot to recover what he was working on. What is odd is that the issue is sporadic; he can edit several different documents in a row without any issues but there are also days where the second form he works locks the system. If he reboots his PC and starts reworking the PDF he has no issues. His PC is fairly new, running Windows 7 SP1 on 16GB of RAM so it shouldn't be a hardware issue. I've tried reinstalling Acrobat and that did not resolve the problem.