[Users] wish : a previous button (following my reading history)

[Michael]

Finally some sudden insight hit me ... maybe the underlying gtk subsystem (or whatever) simply do not evaluate these 'extra' mouse events. And thinking about the situation (with so many laptops, netbooks and handhelds with no mouse at all out there) it might need way too much modifications to implement the feature, compared to the few users who might use it. 
So let me drop this issue here!