"Trust This Computer" Keeps Popping Up Every Time iPhone Is Connected to MBP

Hi,

I found this question of the forum in relation to Windows computer, but not in relation to a Mac (especially, I did not find a solution).

The issue: every time I connect my iPhone (6 Plus, current iOS 8.2.) to my MBP (Mid-2012 13'', current Mac OS X 10.10.2) I am getting the "Trust This Computer" message, despite that I have trusted the computer (like twice daily, about 500 times) already. According to 'Trust This Computer' alert on iPhone, iPad, or iPod touch - Apple Support the iPhone should only ask me once per computer.

What I have done so far:

- updated iPhone from iOS 7 to iOS 8 (and within 7 and 8)

- updated Mac OS X from Mavericks to Yosemite (and within 7 and 8).

- replaced the cable twice (both Apple, from Apple Store, Australia)

- reinstalled Yosemite (for other reasons)

- repaired file permissions on Yosemite (got this from this forum)

- tried different USB ports

Nada, still asking me. In addition to the annoyance, it is the also apparently not syncing with iTunes.

Do I have options left to make the issue go away?

Thank you for your help!