[9.34] Operation Is Not Supported. Again.

[rjsec4ever]

OS: Win8.1-update1 Pro.
Type of Account: Admin.

I've had this issue since 9.20, where I can't add anything to an already existing archive.
I've also been noticing many others having similar issues.

Here are my problems:
- If 7zFM is not set to 'Run As Admin', I am capable of opening archives via context menu, but can't extract to Windows' 'protected' folders. (This one is quite obvious.) I normally do this for other file types like ISO.
- If 7zFM is set to 'Run As Admin', the inverse happens (can't open archives via context menu, able to extract directly to system folders).

Likewise:
- If 7zFM is run under admin, I can create archives from it...
- If 7zFM isn't run as admin, I'm unable to do so. (Operation is not supported.)
- If I create an archive via context menu OR an elevated FM, if I try to add files to said archive, elevated or not, I get the same 'Operation is not supported.' error.

All I'd like to do is be able to add files to already-made archives, and to open archives via context menu. Maybe make the program always run as admin?

EDIT: I'm able to add to archives with two elevated instances of 7zFM. It shouldn't be necessary.