I'm guessing Csus2...
http://www.8notes.com/guitar_Chord_chart/Csus2.asp
Also when they list the chords with a capo, I'm thinking the chord is the "chord shape" relative to the capo and not the actual chord itself. So a C with the capo on the 4th fret would be an E. That means the G/B would really be a B/Eb.
Maybe someone who knows this better can say if that's right or not.