Large uncertanties

[vetlewi]

Using the following input:
Beam: 132Xe, Energy: 529.91 MeV
Target: 2H

dE/E detector material: Si
dE detector width: 1000.00 um
E detector width: 1000.00 um
Absorber material: Al
Absorber width 10.5 um

Fragments: Protons+deutrons
Angle 47, SiRi strip 0.

Gives uncertainties with several MeV. Why is that? Is that correct?