Make sure the avast plugin is not disabled into MS Outlook:
Outlook 2007 > Tools > Trust center > Add-inns > Manage Disabled items.
Outlook 2003 > Help > About > Disabled items.
Outlook 2002 > Help > About Microsoft Outlook > Disabled items.
Outlook 2000 > Tools menu > Options > Other > Advanced Options > Add-In Manager.
The message “The provider is waiting on the subsystem to start” will be shown there until you open MS Outlook.
The plugin will be enabled automatically after that.
Do you use Outlook (not the Express)?
Then it shouldn’t run by default is MS Outlook isn’t installed, so it could be you have been tweaking avast.
However, two things you mentioned:
6/7 providers running is normally correct if the Outlook/Exchange provider isn’t running.
Since the ‘waiting for a subsystem to start’ message often means that the Outlook/Exchange is running and waiting for MS Outlook to start, then it would mean another provider isn’t running.
So can you tell us exactly what provider isn’t running ?