  We revisit the computation (hep-th/0306130) of 1-loop AdS_5 x S^5 superstring
sigma model correction to energy of a closed circular string rotating in S^5.
The string is spinning around its center of mass with two equal angular momenta
J_2=J_3 and its center of mass angular momentum is J_1. We revise the argument
in hep-th/0306130 that the 1-loop correction is suppressed by 1/J factor (J=
J_1 + 2 J_2 is the total SO(6) spin) relative to the classical term in the
energy and use numerical methods to compute the leading 1-loop coefficient. The
corresponding gauge theory result is known (hep-th/0405055) only in the J_1=0
limit when the string solution becomes unstable and thus the 1-loop shift of
the energy formally contains an imaginary part. While the comparison with gauge
theory may not be well-defined in this case, our numerical string theory value
of the 1-loop coefficient seems to disagree with the gauge theory one. A
plausible explanation should be (as in hep-th/0405001) in the different order
of limits taken on the gauge theory and the string theory sides of the AdS/CFT
duality.
