Can't Unbind Keyboard shortcut

[Billy86]

So, I'm trying to unbind "Copy from Screenset 1" from CTRL+1 . I don't want that shortcut assigned to anything in CbB because I want to assign it to ZoomIt while running CbB.  (It allows you to zoom into any part of your screen, my workaround because some of the type fonts are so small for me. 

I go to Preferences-Keyboard Shortcuts. I do all this, from the online help site: 

Save Changes for Next Session

Select this check box to save any changes.

Unbind

Click this button to unbind a highlighted key from a highlighted function.

I highlight CTRL+1 in the Locate Key box, I click "Unbind" and I Save, with "Save Changes for Next Session" checked. I close CbB and relaunch. And the CTRL-1 key is still bound to  "Copy from Screenset 1." What am I missing?

Thanks. 

[scook]

In the Global area is a function called "Do Nothing: Use to block pre-defined accelerators"

Try binding the key combination to this function.