New version released that fixes the issue with starting Jaikzo 4.5.6 on a new installation, sorry for the problem.
Jaikoz 4.5.7 Released on February 4th 2012
Loving the changes made in 4.5.6 / 4.5.7! Program is running smoothly and the musicbrainz matching is returning even greater results.
Keep up the awesome work! 