  Many string theories contain states which are not BPS, but are stable due to
charge conservation. In many cases the description of these states in the
strong coupling limit remains unknown despite the existence of a weakly coupled
dual theory. However, we show that in some cases duality symmetries in string
theory do enable us to identify these states in the strong coupling limit and
calculate their masses. We also speculate that in some of the other cases the
missing states might arise from non-supersymmetric analog of D0-branes.
