Users have reported issues with connecting their iPhones 5 to Ubuntu 13.04 and 13.10. The iPhone reports "Trust the currently connected computer?" When the users selects 'Trust', it continues to ask.
https://bugs.launchpad.net/ubuntu/+source/libimobiledevice/+bug/1207812
Best Answer
I recently checked out the bug tracking page and I noticed a solution. The solution is to download libimobiledevice4_1.1.6-git20140105_amd64.deb. This can be found here:
https://launchpadlibrarian.net/161787269/libimobiledevice4_1.1.6-git20140105_amd64.deb
Once downloaded, point your terminal to the location of the .deb file and execute the following:
According to the bug page, other users have reported having success with this update library as well.
https://bugs.launchpad.net/ubuntu/+source/libimobiledevice/+bug/1207812
I downloaded this and was successful with connecting my iPhone 5.
Update
Just want to clarify that this lib is currently for 64-bit versions of Ubuntu 13.04/13.10.