Bug#359172: libgtk2.0-0: scrolling much slower in gtk 2.8

[John Belmonte]

I confirm this.  Recently when upgrading my scite editor from sid I
pulled in gtk 2.8, and painting generally feels an order of magnitude
slower, which is especially noticeable in scrolling.  When I did a
custom build of the same scite version for sarge and downgraded libgtk
back to sarge version the problem went away.

I think this bug should be higher severity than "normal".