Version:           2.2.1 (using KDE 3.1.3)
Installed from:     (3.0)
Compiler:          gcc version 2.95.4 20011002 (Debian prerelease)
OS:          Linux (i686) release 2.4.21-tc2

This is a gui inconsistency.
It stems from the change from playlist play-on-double-click to play-on-single-click.

If I want to manipulate the playlist without playing the tracks I'm touching, I need to use the right mouse button for selecting.

Now consider selecting a set of tracks and moving them to the start of the playlist.
Old version (KDE 3.0): left-click first selection - shift-left-click last selection - left-drag group into new position.
New version (3.1.3): right-click first selection - shift-right-click last selection - (hypothetically) right-drag group into new position.

BUT
actually, right-drag in the new version only creates a new group selection rather than moving the selection.

Solution: shift- and ctrl-right-click are sufficient to select any group, so please turn off group selection and enable drag-and-drop on right-drag instead.

Cheers,
drushka