No effect at all. As the other review claimed otherwise, I'm going to assume Xtube broke it themselves.

A great little script that gets rid of the annoying popup sign up screen which starts to appear after viewing a number of videos.
There are no conflicts with any other scripts or add-ons that I have installed.
Like the author says it bypasses the nag screen completely.
What more could you ask.

EDIT 11-May-2010
MrLore said it did not work and Xtube must have broken it themselves. This is not true as it still works OK for me, so it may work for some users and not others. It does work honest although you may see an initial tab appear for a split second before disappearing completely.