  The transverse energy spectrum in the unit rapidity window in p-bar p
collisions at 540 GeV c.m.s energy is calculated to the next-to-leading order
accuracy O(a_s^3) and compared to the experimental data by UA(2) collaboration.
We show that the calculated spectrum starts matching experimental data only at
relatively large transverse energy Et=60 GeV and is in essential disagreement
with it both in shape and magnitude at lower transverse energies. The data are
well reproduced by HIJING Monte-Carlo generator indicating the crucial
importance of all-order effects in perturbation theory as well as those of
hadronization in describing the transverse energy production in hadron
collisions at small and intermediate transverse energies.
