Problems with Intellisync for Yahoo and Palm OS

I seem to have an ongoing problem with using Intellisync for Yahoo with my Palm Zire 72. I can synchronize my calendar no problem, but when Intellisync for Yahoo tries to sync my Yahoo Address Book or Tasks (To do items), I get the error message “Unable to sync application data” and then when I try to go to my Yahoo Address Book or Calendar, it is inaccessible for about 15 minutes. I think that it is corrupted, and that Yahoo is restoring it from a backup. Does anyone have any ideas or suggestions?