I'm the Salesforce Admin for Mozy by EMC's inside sales group. Some of my users are attempting to use the Salesforce Zimlet on their MAC machines but keep getting the following error:

"An error occurred while initializing the zimlet "com_zimbra_sforce". TypeError e.getTreeItemById is not a function"

Some of the Mac users are running fine whilst others are receiving the errors. I've checked all their Salesforce settings and both those that get the errors and those that don't have identical profiles and settings. Any clues on this one?