can not back up iphone

[vietkool]

I got a iphone using ver 3.0 unlocked now and just restored the contact from my back up just fine. Then I try to do the backup contact gain. WHen I right click at the iphone from device, then choose back up, it pop up the msg said " itune could not back up the iphone becase the iphone disconnected"
but the iphone still connect to the USB. anyone have same problem? how to fix it ?

[vietkool]

here is the snap shot of the msg

[vietkool]

any help guys. I restored the phone, jailbreak and unlock again, everything when oke, backup and sync oke.. then I add Intelluos source and some games from their site, upgraded cydia then I do the back up again. this time it show the same msg " can not backup because iphone disconnected" ...
any suggestion guys?

[blkcadi]

could be Karma, no clue just sayin'

[vietkool]

I did some research, it may effect by Mobile path or something but I got no idea what is it and how to remove the mobile path...