Playback won't work NLA

I am having some issues to have the playback work when on Blender 2.66 NLA window. Once i have added trips, the play back is no longer working at all, on any window including the timeline window. All doc i found is related to Blender 2.4, which is outdated.
Please help.

If it was a bug maybe it was fixed in the last 6 months since that version of blender was released. Try with the current blender version

In the timeline Playback menu check you have other editors enabled

Make sure you haven’t muted anything (speaker icon) or toggled solo mode (star) on any track