I have been doing it that way for 2 years or longer. Had to do it on my Apache as well. I never had an issue with erasing them. I did decide to run PIM backup to put my contacts on my phone once, then I ran Active Sync and it duplicated all my contacts. That took about an hour to fix. I do keep a copy of my contacts on PIM bacup in case I am away from my PC and have to hard reset. I then hard reset again when i get home before I run Active Sync. I am running Outlokk 2002 lol. I don't use it to check email, I just use it to sync.