Read 10 pages of community chatter - tried everything I could. Looks like many PC users have a fix for this problem but I haven't seen anything specific for the Mac.
Last night, I installed the latest upgrade 7.1 my iPhone 5. When I connect to my main laptop (Mac Book Pro, Intel Core 2 Duo processor and running on OSX 10.9.2), I'm asked if I want "Trust This Computer?". I select TRUST, wait about 30 seconds and it asks again. I'm stuck in a loop.
I'm using the offical iPhone cable, rebooted my phone and my laptop, reset my iPhone settings, reinstalled iTunes on the laptop, have plenty of space on my computer & iPhone and still no success.
To make matters more frustrating ....as a test, I pulled out my second laptop (another Mac Book Pro), which I travel with, and it trusted that device so I guess the issue is a laptop issue.