Solution is to remove registry key "Computer\HKEY_CLASSES_ROOT\exefile\shellex\iconhandler"
I don’t know why this key is created when you install IconPackager, the program does not handle .exe files. The only reason to have this entry is when a .exe does not have an icon associated in the .exe, creating a generic .exe icon. But it changes the default icon that other programs read, such as Object Dock. Removing this entry reverts the registry to a default of "%1" which is the icon that is normally associated with any program that is installed. A generic .exe icon is not really needed.
All system tray icons also revered to the defaults (no generic blank icons).
As a side note, you can revert any extension association this way, to find the file association, go to registry "Computer\HKEY_CLASSES\ROOT" find the extension you want to revert and go to the registry entry named under default to change the icon handler. Not all extensions have icon handlers or defaults. if no default entry is present, you can make the extension associate with any icon you wish by creating the sub key "DefaultIcon" and a "(Default)" string value pointing to whatever icon you wish. You can use relative or full paths in string.
This may be resolved also, by changing the "DropHandler" key entry for exefile associations. For this extension, it would make more sense to add the IconPackager entry into the "DropHandler" Key. (info for the programmers)