  It had been proposed earlier that the hard X-ray and gamma-ray radiation of
the Be/X-ray system LSI+61o303 could be due to inverse Compton scattering of
optical photons from the Be star by the same electron population which also
produces the radio emission. Recently, Apparao (2001) has calculated this
inverse Compton emission in more detail, and predicted that the X-ray spectrum
should show a break at around 20 keV. We investigated archival RXTE data, but
do not find such a break in the 2--25 keV range. The implications of this
finding are shortly discussed.

Astrophysics