Puntuado con 5 de 5 estrellas

Finally, after disabling all add-ons, I have reactivated all, one by one (or more precisely two by two) starting with ImageTweak and the bug has mysteriously disappeared! --- (I remind you what was the original problem: "since the last update (version 0.22), it is impossible to close the first tab") --- Now, there is no problem.

Esta valoración es de una versión anterior del complemento (0.22.1-signed.1-signed). 

Puntuado con 4 de 5 estrellas

May 21, 2011 : This add-on is very useful, but since the last update (version 0.22), it is impossible to close the first tab. Can you fix this bug? Thank you. ----- May 24, 2011 : [Firefox 4.0.1 - Windows XP SP 3]. Finally, after disabling all add-ons, then have reactivated all, one by one (or more precisely two by two) starting with ImageTweak, the bug has mysteriously disappeared!

Esta valoración es de una versión anterior del complemento (0.22.1-signed.1-signed). 

I can't reproduce the problem. Please test if it happens also with a clear profile with no other add-ons beside ImageTweak. If it still happens, please paste your UA signature (you can find it in about:support)