(2nd try) ubuntu 12.04LTS: sometime won't detect my iphone4s!

[ping]

On 11/13/2012 04:44 PM, ping wrote:
> folks:
> not sure you guys expericence the same,  sometime my iphone4s can't be 
> recognized when I connect the USB cable into ubuntu PC.
> previously I had similiar issue with blackberry and in that case can 
> be constantly resolved by:
>     $ sudo modprobe -r usb_storage
>     $ sudo modprobe usb_storage
>
> but now this doesn't work, any known solutions?
>
> thanks!
> regards
> ping

guys, anyone can help here?