Permissions
If you're having a permissions problem, you have to fix it before kJams will behave correctly.
eSellerate
Navigate to your /Library/Frameworks folder (at the root, not in your Home folder). Is there a folder called "EWSMac.framework" in there? Delete it. Now run again, does it work? Then you're good. If not, Get Info on the "Frameworks" folder itself, and set write permissions (see below).
QuickTime
Navigate to the folder "/Library/Application Support/kJams Plugins". Did you find the "kJams Plugins" folder? If not, make one. If you can't then Get Info on the "Application Support" folder and set write permissions (see below). If you DO find the "kJams Plugins" folder, get info on THAT, then set write permissions on that.
Setting Write Permissions
In the Get Info window, reveal the "Sharing & Permissions" panel. Click the Lock icon and enter your password. Now next to "everyone", set the popup to "read & write". Actually set that for all "Names". close the window. You should be good to go.