in Nero, in the Audio compilation window, right click the track -> Properties, in the Pause entry enter the length of pause you want (or 0).
you can highlight all tracks and do the same it sets the same pause for all inter-track gaps at once!
One Ring to rule them all, One Ring to find them,
One Ring to bring them all and in the darkness bind them
In the land of Mordor, where the Shadows lie
M.C. Escher - Reptilien