i don't use an x3, so i can't say much about the OS, but i do know that, if left un-used for a long time, the battery drains completely. when this happens, the backup battery is used. once the backup battery is drained, the device looses all of the data in it's volatile memory (i.e. RAM). whatever was on a storage card or in built-in storage should still be there.
sorry to hear what happened...i hope you have a backup!