Evidentially not. I have never heard of this happening before. Sounds like your computer deleted everything...both on your phone and on itself.
I've never owned a chocolate, but Verizon's UI should be the same on all their phones, so to check what version of firmware your running, go to:
Menu
Settings & Tools
Phone Info
SW/HW Version
Look at your SW Version and that will tell you your firmware version.
Changing your firmware will do nothing to your phone for the most part. It will update certain things of course, but if your worried about losing stuff like your ringtones, contacts, wallpapers, etc....don't worrry about it.....they won't be touched.