I've just bought a 16gb Sandisk microSD and I moved some apps to that by using the functionality available under
Settings > Applications > Manage Applications. I went through the list and I moved some apps to the microSD when the button was available. I also moved the Music folder to the new microSD.
Then I left my phone for a while and when I came back it was asking me for the PIN code as it had restarted. Then the Android configuration wizard popped up, like when you first boot the device (so asking me to choose the language and set other configuration things). After this I found out that my previous data was gone including contacts, text messages, settings, etc. Similar to when you do a hard reset. Some things remained like pictures and music files.
Unfortunately there's no sync with Google or similar. I should have done that or at least made a backup before moving things to the new storage.
I believe my data is still there somehow. I'd like to know if my things are completely gone or maybe they are just not loaded for some weird reason. Can you help me?
Phone: Samsung Galaxy S Plus (GT-I9001) / Android version: 2.3.5
EDIT: After completely reformatting the microSD as also suggested by official SanDisk tecnical support for general problems, I didn't experienced another hard reset so far after moving files.