My experience with avast! auto-sandbox has been very limited. Since I installed version 7.0 it has been non-existent.
When I was running avast! AIS 6 on W7 Radio Sure would get auto-sandboxed.
When I replaced W7 with W8-DP I had to switch to Windows Defender. Radio Sure ran fine with no problem.
When avast! AIS 7 was released I replaced Windows Defender with it on W8-CP which I had upgraded to from W8-DP. avast! AIS 7 has never asked to auto-sandbox Radio Sure on W8-CP
One thing about W8-DP, W8-CP and I imagine the final release of W8 is that it does a very good job of checking the installation executable when you go to install a program. In fact it has blocked a couple of 3rd party programs from installing that I wanted to install. They could have been malicious hence a block or just not on Microsoft's Security Assurance list hence a block. Since W8 is blocking programs from installing this could explain why I have never had avast! AIS 7 ask to auto-sandbox anything. Whatever avast! is looking for as a possible auto-sandbox candidate W8 prevents from installing in the first place hence nothing for avast7 to find and auto-sandbox.
I have no idea of why Radio Sure was but is no longer being captured by auto-sandbox. Could be a change in Radio Sure, a change in auto-sandbox and/or due to W8.