I've attached a fixed .reg file. This is an export of the Folder Open key for Explorer (i.e. Opus set not to replace Explorer). Delete the existing Open key before importing this one:
HKEY_CLASSES_ROOT\Folder\shell\open
I just had a thought about what may be causing the problem. Can someone who is experiencing it check the Folder Open key under these two locations:
HKEY_CURRENT_USER\Software\Classes
HKEY_LOCAL_MACHINE\Software\Classes
Perhaps the problem is caused by the way HKEY_CLASSES_ROOT is a merge of those two locations, and only one of them is being updated when you change settings in Opus. In particular, a non-admin account may not be able to change the HKLM value which may lead to confusion and/or different things happening in different accounts (which is even more confusing when the shell and Opus are running under different accounts within the same session).
Folder_Reg_HKLM.zip (568 Bytes)