ITunes Error for 10.3.1

I had the problem with error -50 on both my IPhone 4 and Ipad. stopped by Apple store yesterday. I didn't have the update 10.3.1 so that was downloaded. We tried it again.

This time it just says: can not backup the IPhone, same with Ipad. It does the prosses, it looks like it's working. But at the end, it say's - can not backup with NO error code.

In addition, when the Iphone is still hooked up to the computer. we can see the music library from my IPhone on my computer but and even play the song from it, but when we looked at the IPod section from my IPhone, my hole library is GONE on bot my IPone and IPad. The Gentelman the Apple store suggested to restore my Iphone as if it is a brand new phone.

Have not tried it yet. Would like to know if anyone else is having the same problem.

I have a Mac Pro. everything is updated on my Mac, IPhone and IPad as of yesterday. Any suggestions would be appreciated.

Thanks