  A measurement of the ttbar production cross section at sqrt(s) = 1.96 TeV in
the dilepton final states using a lepton+track selection and secondary vertex
b-tagging is presented. One of the two leptons from the decay of the ttbar pair
is allowed to be identified only as an isolated track to improve the selection
efficiency. The result is combined with a measurement in the ttbar->e+mu final
state. The measurements are based on 370 pb^-1 of data collected with the D0
experiment at the Tevatron collider. The preliminary cross section obtained in
the combined lepton+track and e+mu channel is: sigma_{ttbar} = 8.6 +1.9 -1.7
(stat) +/- 1.1 (syst) +/- 0.6 (lumi) pb.
