  A gap in the proof prevents us to show that surfaces with constant mean
curvature closed to 1/2 in H2 X R and having boundary with curvature greater
than one, contained in a horizontal section P of H2 X R are topological disks,
provided they are contained in one of the two halfspaces determined by P. This
is the analogue in H2 X R of a result in R3 by A. Ros and H. Rosenberg [13,
Theorem 2].
