iPhone 3GS wont backup?

[smlfri]

Hey Guys
As of recently my iPhone 3GS wont backup to itunes. I have tried control clicking my phone under devices in iTunes but it does not offer backup. That is supposedly the way to manually backing up your device according to apple. I do not know if it is because i deleted all the old backups from preferences>devices (trying to save HD space had about 30 GB of old backups from other devices). Can someone please help me solve this problem because my phone has being a little weird after updating to 4.0 and would like to restore but don't want to have to make my folders and ect. again
Thanks

 

[Neeliosis]

Dude! I'm getting the same problem, with all of my iDevices! I've deleted all of my backups, and deleted the preferences file.

 

[smlfri]

How did you manage this?? maybe that is what i have done as well and we just need to replace the file??