I love that my contacts will now automatically be uploaded to the web and that I'll never have to worry if I lose my phone, etc. After my second or third auto-sync, some of my contacts were missing, and several others were duplicated. What the..??
Yeah, I had problems with that. I think it was due to the fact that I had uses Wireless Backup on one of my old phones, and when I got my Instinct I had my numbers transfered from my Blackberry to my Instinct. Some numbers disappeared, some were in there 3 times. I deleted them all and refreshed them onto my phone... One week later only 53 out of 114 are uploaded ot the Mobile Sync website.
Mine has worked fine except for when i tried to import a csv (even though it was generated by exporting from the site.) It gave an error about a malformed contact (or something like that), and then would not sync or allow me to export the contacts. The problem went away when i turned off autosync, deleted everything from the website, and then turned it back on. I haven't tried to import anything since then.