That's odd. Make sure you have "play every frame" in your options. Also if you loaded a file perhaps you have 30 fps in your prefs, in which case the start frame might be a fractional frame. If so, reset your playback range to start exactly on 1.
Also make sure you have nCloth toggled on in your panel "show" menu. Otherwise the turbulence field( which helps break up the bits ) will only evaluate the first time through( this is a current bug with fields applied to nCloth).
Duncan