I am running the latest Firefox Nightly (2014-02-02 at the moment of speaking) and the latest development build of NoScript (2.6.8.14rc1 at the moment of speaking). Here are the steps to reproduce this bug:
- Make sure scripts are forbidden globally;
- Open a new tab;
- Type something into the Awesome Bar (Firefox's address bar; the one you use to enter URLs in and stuff);
- Allow scripts globally;
- Now, you cannot navigate to the address you typed into the Awesome Bar, no matter if you press Enter, Ctrl+Enter, or any other combination that can be used. If, however, you switch to another tab and then come back, everything will be just OK.