Hi,
I am using avast internet security 5.0.594 and when I sandbox Opera, avast prevents Opera from saving settings. Under process virtualization I checked the box that said 'All settings' but still Opera was unable to save it's settings. Adding an exclusion to C:\Users\UserName\AppData\* solves the problem, but it would be nice if avast let Opera save it's settings automatically. I am using Windows 7 home premium 64-bit and avast Internet security is my only active protection.
Edit: avast sandbox also prevents flash player from working in Opera. When using Opera sandboxed, Opera gives this message: "You need to install the Macromedia Flash Player plug-in to view all content on this page. Do you want to download this plug-in now?"
But I already have flash player installed, and flash player works fine if Opera is run without the sandbox.