Rated 5 out of 5 stars

yazan: sailor1231 tarih: Eyl. 2, 2012 ·

- Add option (check box) to show/hide context menu item ...

Thank you ...

This review is for a previous version of the add-on (2.2.1-signed). 

yazan: David Adler (Geliştirici) tarih: Eyl. 2, 2012 ·

I do plan to add an option for that; you can track the issue here:
https://github.com/dadler/thumbnail-zoom/issues/90

In the meantime, a workaround is to install the Firefox add-on "Menu Editor", which lets you hide that menu item.