I tried an earlier 1.4 beta version a few months ago on Win2k and had problems so I reverted back to 1.3.1.
I just upgraded to XP which I think has 1.3.1, and am referring to having just upgraded that to the latest 1.4beta. XP overall is much better than I experienced with 2k, but on top of that, this new 1.4 release quickly takes it to another level for me.