  The KLOE experiment has collected 2.4 1/pb of integrated luminosity during
the commissioning of the DAFNE phi-factory in 1999. The performance of the
detector has been studied using phi -> KL KS decays collected during this
period, yielding also first measurements of relevant K parameters such as
masses and lifetimes. A clean Kshort -> pi+ pi- sample is used to select Klong
-> 2pi CP-violating decays and Klong -> Kshort regeneration events in the
detector material. Results on the regeneration probability in
beryllium-alluminum alloy and carbon-fiber plus aluminum composite are
presented.
