Modal shows off screen

When clicking the "add node info" button, the modal dialog shows half way up the top of the screen.

In firebug:
topMeasure -118
topOffset 179

If I remove the minus in line 23 of advupload_nodeinfo.js, it shows on screen.

Using advupload 6.x-2.6 and advupload_nodeinfo 6.x-2.6.
$().jQuery returns 1.5.2
Drupal 6.22