  The importance of contributions due to the longitudinally polarised virtual
photon and the longitudinal-transverse interference term, in the unpolarised ep
collisions is discussed. The numerical calculations for the Compton process, e
p --> e gamma X, at the HERA collider were performed in the Born approximation.
The various distributions in the ep centre-of-mass and Breit frames are
presented. These cross sections are dominated by the transversely polarised
intermediate photon, even for large values of its virtuality.
