Processes disappearing from active process list.

I encountered a curious bug today, the no. of active processes in the summary screen(under the pro-active defense tab) says that there are 35 processes active(same as indicated by task manager/process explorer) but the actual list contains far less, it seems that the entire explorer.exe and its children had disappeared, the only processes that are shown are launched under NT AUTHORITY/SYSTEM, the USER launched processes are absent, while this is not a big issue as I mainly depend on PE/Task manager but the main issue is whenever I want to white-list/blacklist any process it gives me that incomplete list.

If I launch any process further, then it shows in the list but not under any parent(they should be under explorer.exe)

The problem occurred after some defense+ alerts in which I selected the apps as trusted, I played a game for some time after that, after that the issue crawled up.

1.Intel E8400/4GB RAM
2.Windows XP SP3 32bit
3.Avast Antivirus 5 running in background
4.Firewall Setting - Custom Policy Mode
5.Defence+ Setting - Safe Mode, Sandbox - Disabled
6.Running as admin
7.Comodo 4.0.141842.828

I have not been able to reproduce the problem yet, it got fixed after a reboot.

3 Images of the bug has been attached.

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