I have admittedly not tried very many variations as I need evidence that it works first. What version of tracks are you using with what version of Drupal? This is my setup and I am havinga rpoblem as mentioned in the post on [http://drupal.org/node/474254]

Tracks v 6.x-0.x-dev
Gmap v 6.x-1.1

Drupal v 6.22
MySQL v 5.1.57
PHP v 5.2.17