I am having this error "Javascript Application - Couldn't access Yahoo! Zimbra Desktop server. If issue persists after reinstall, please check logs for errors and report to http://www.zimbra.com/forums/zimbra-desktop." I am using a Mac. I have tried to uninstall it and reinstall it several times. After reinstalling, it would work for awhile, then it would do the same thing again. any ideas on how to fix this?