Iphone 4.0 on itunes install

Hello,

while installing the last version of the software for iphone 4.0 on itunes came out: a problem occured while restoring the phone (50)....i didn't do the back up before installing hoping that all the apps would have stayed.

Now it seems that the version i have is the old one even if in itunes it says that the latest version is updated...
another thing is that all the contacts and messages messages from the 29 of may 2010 til today have been deleted....
what the hell is happening????
can somebody help me?

thanks