Mouse scrolls half the window height

[Mikhail Ramendik <mr ramendik ru>]

Hello,

In Gtk2 applications, notably Evolution 1.4.x, in text/html views (i.e.
email), the mouse wheel scrolls all of half the window height in a
single movement - whatever that height. This is somewhat inconvenient,
especially with tall windows.

In other apps, notably Qt apps, Mozilla and Evolution 1.2.x, the mouse
wheel scroolls 3 lines, as I believe it should.

Is there a way to get gtk2 apps to behave like this also?

I do have Gnome 2.4 installed (but not used). I fired up
Gnome-Control-Center, but found no setting like this. 

A Google did not help.

Any help will be greatly appreciated.

Sincerely yours, Mikhail Ramendik
Moscow, Russia