Rated 4 out of 5 stars

by velinho on Nov. 5, 2008 ·

version 0.16 was great, but in versions 0.17 and 0.17.1 zooming pictures with mouse wheel does not work for me. So I also had to downgrade back to ver. 0.16.

This review is for a previous version of the add-on (0.17.1). 

by Carlo Alberto Ferraris (Developer) on Nov. 6, 2008 ·

From version 0.17 onward, the default zooming control has changed to be consistent with firefox's built-in one.
As such, you now has to do ctrl+wheel to zoom (this is the same command used on webpages) and wheel to scroll vertically: this is meant to ease new users that may be used to the standard command.
You have therefore to choose: you can use the new command (rest assured that no-one better than me knows how painful it is: I originally coded this extension for myself and I've been using it with the old control for years!) or go in about:config and set extensions.imagetweak.legacyscrolling to true (this is explained in detail in the online help http://cafxx.strayorange.com/ImageTweak%20Help).
Hope this fixes it for you.