Defence+ does not always work when safe application is updated

I have had this issue several times. When an application is updated defence+ does not always trust the new version when it should until the PC has been restarted. This has happened with Firefox (a trusted signed application)
https://forums.comodo.com/news-announcements-feedback-cis/clean-pc-modesandbox-does-not-work-as-expected-t54747.0.html and now XnView (not signed) and at least one more time but I forget which application. Firefox was sandboxed until I rebooted and XnView was not allowed to be opened by explorer until I rebooted (auto sandboxing was off this time). The blocking was clear in defence+ log (blocked as I have parental control on). After reboot everything works perfectly.

I use clean PC mode with parental control on and remove everything from my pending files after installation. There should be no reason for defence+ to block the new version. It is as if there was some confusion in defence+ caused by the version change.

The latest occurrence was with CIS 4.1.150349.920 with defence+ AV and firewall all active. This was after a complete reinstall of CIS when I put on 4.1.

The Firefox issue was with CIS 4.0.138377.779 on the same PC.

Windows 7 64 bit no other security applications.