disable the tracker in questhelper
i think the command for it is:
/qh track
otherwise summon the commandlist from questhelper to see if its a somewhat other command, but i honestly think its the questhelper tracker you have issues with.
besides, nQuestlog offers a full questlog and tracker replacement, but if you install questhelper as well, you'll always get the tracker from questhelper when you first login after installing it (which is not needed when combining the 2 addons)
Greetz,
CM