I used Subtitle Processor under Windows XP.
1.) Subtitle Editor (from Synaptic): something is wrong with the input methods and I cannot type in anything, and I don't like the environment either, so Subtitle Editor is DROPPED.
2.) AegiSub: nope, it didn't play the sounds, and I didn't like the environment.
3.) Gnome Subtitles: LIKE :-) Can do shifting easily.