Version:           0.1.0 (using KDE 4.1.3)
OS:                Linux
Installed from:    SuSE RPMs

I enabled the "Desktop Grid" effect to quickly switch between virtual desktops. It uses a "scrolling" effect to visualize the move from desktop to desktop.

In my configuration, I have set up four desktops which are arranged in one row (configured via the pager plasmoid settings):

 [ 1 ] [ 2 ] [ 3 ] [ 4 ]

I can properly switch left and right between these desktops with the configured hotkeys (Ctrl+Alt+Left/Right).

However, the Desktop Grid switcher seems to assume that the four desktops are arranged in two rows like this:

[ 1 ] - [ 2 ]
      X
[ 3 ] - [ 4 ]

The scrolling effect displayed when switching between desktop 2 and 3 or from 4 to 1 (and back) results in a vertical movement as well, while moving between 1 and 2 or 3 and 4 correctly visualizes this by a horizontal scroll only.

I assume the Desktop Grid Switching effect needs to query the pager plasmoid for the actual desktop layout.