As far as my experience goes, you won't lose your data but your settings when you flash your device. That means that you may have to reconfigure your email accounts and so on but you won't lose the pictures or whatever you have on your phone. Don't know about the Ovi Suite as I do not have one... for this release I installed OTA (over the air) and didn't need a thing and for the previous times I used the flasher on Linux... sorry about that