Newbie Multiple Audio Track Problem

[lineranch]

Hi there,
I am new to audio recording and am trying to do a simple two track voice recording. I lay a voice down on one track, then record a second track, which seems to be recording fine. However, when I stop recording, the second track is blank. I have enabled "Play other tracks while recording new ones" but the problem remains. However, if I disable it, the second track records fine, but I am obviously unable to synch my voice to the first track as I can't hear it. Anyone come across this problem or can help? Thanks