Rated 5 out of 5 stars

Now it's working and very useful :D :)

I have a hungarian keyboard and settings... that could be a problem.. because it is non-english.

This review is for a previous version of the add-on (0.1.0.1-signed). 

You can change extensions.privateTab.key.toggleTabPrivate preference in about:config page, see
https://github.com/Infocatcher/Private_Tab/blob/master/defaults/preferences/prefs.js
for some descriptions.

But this is strange, the shortcut should be Ctrl+Alt+V.
Which keyboard and which keyboard layout you use?
What shortcut for "Private Tab" menu item shown in context menu of current tab?

And you can try revert changes of this issue:
https://github.com/Infocatcher/Private_Tab/issues/19
=> https://github.com/Infocatcher/Private_Tab/issues/19#issuecomment-16103910


Also please set extensions.privateTab.debug to true in about:config page and provide information from Error Console (Ctrl+Shift+J).
Hotkeys initialises on startup or extension enabling/updating, so just install it again to get all messages and errors.

Messages should looks like
[Private Tab] ...
And errors/warnings:
Error: ...
Source file: resource://gre/modules/XPIProvider.jsm -> jar:file:///.../extensions/privateTab@infocatcher.xpi!/bootstrap.js

(You can post report here: https://github.com/Infocatcher/Private_Tab/issues or here: http://forums.mozillazine.org/viewtopic.php?t=2665169)