Fusion theme is oriented toward integration with Skinr module, and in order to use all its capabilities one should have the 2nd branch of Skiner installed + module Dialogue (for UI), though, for releases of modules are not yet accessible (so far, we've only used devs) it causes some bugs to come about. As everything is oriented at Drupal 7, modules for v.7 are updated almost every day and v.6 will be updated much more seldom.
To make sure everything works well on v.6 we sould install the following:
1)Fusion theme itself
2) Skinr 6.2.x
3) Jquery Update 6.2.x
4) Jquery UI 1.7