Itunes synq problem wire & wireless

Hey,

first of all I am sorry for my bad english!

Let's come to the point.

I tryed to synchronized my Iphone 4s with Itunes... the library (music). In the first moment it looked good, but after 5 seconds the new music dissapeard on my Iphone. I have the wlan sync function abled on my Iphone. It doesn't matter what I try to sync. It always resets it to the point I was before.

What did you "fix" ?

ps. I know. Turn wlan sync. off....

Please help. Thx!